Transparent mining, or What makes Nxt a 2nd generation currency

[Come-from-Beyond]

Below u'll find a short description of Nxt mining system. The description is based on text written by BCNext, I paraphrase it in my own words to protect BCNext's real identity against text style analysis (as was agreed).

I want u to pay attention to a paper titled Decentralised Currencies Are Probably Impossible But Let’s At Least Make Them Efficient.

The author writes:

To match this to the notion of “decentralised” (i.e. lacking central authority), the consensus group must be, at least, all participants in the currency. This does not present any real problem when that group is known. For example, it would be possible to define the group as “all people currently in the United States”– where the currency would be something akin to the US Dollar. Assuming the majority decide to behave honestly (as seems likely, after all, that is what happens now), then they should have no difficulty in forming consensus on who has how much money at what time. However, the most general notion of decentralisation does not admit such re-strictions. After all, in some sense, placing any such restriction simply pushes the central authority back a layer: instead of controlling the currency, the authority controls membership of the consensus group. A system like this must allow any entity to participate, and to join and leave the scheme at will. And here lies the problem. If you can never know who is in the scheme (bear in mind that knowing who is in is also a consensus problem!), then you can never get agreement.

In Nxt this problem doesn't arise coz all participants (miners) r known. This is a side-effect of 100% proof-of-stake currency. So, let's move to the most interesting part...

As u may know, Bitcoin et al. can be attacked by an entity that possesses 51% of hashing power. 2 main scenarios r possible:
1. Part of the miners leave the "legit" branch of the blockchain and start mining their own branch.
2. Someone buys/produces mining equipment and starts mining secret branch.

The 2nd scenario can't be applied to Nxt, coz no NXTs exist outside the network. Let's look closer at the 1st scenario.

Yesterday the average base target was ~700%. This means that only 1/7 of all stakeholders were generating blocks, we can't say if the rest 6/7 were hit by bus or trying to fork Nxt blockchain. This is in the current Nxt implementation. BCNext is satisfied with the results shown during last 2 weeks and now is going to adjust the mining algo a little bit to make it transparent.

What does this transparency mean? It means that anyone can predict (with very high probability) who and when will generate next block(s). And this gives us superior advantages:
1. Transactions can be sent directly to the miner who will mine the next block (if he decides to reveal his location on the Internet), thus saving traffic and coming much closer to VISA/MasterCard processing volumes.
2. Blocks can be generated in advance and sent to most of the miners before they become valid (timestamp validation), thus greatly reducing rate of orphaned blocks.
3. Due to ability to predict timestamps of future blocks (rate of blocks) it becomes possible to set appropriate fees to assure quick confirmations for important transactions (without paying too much for inclusion into a block).

And the most important feature:
The network can detect which miners don't take part in block generation and act accordingly.

The last point deserves to be described with more details.

Imagine someone is going to do a "51%" attack against Nxt and he owns 90% of all coins. The adversary must stop generating blocks for legit branch coz he won't be able to compete against 100% mining power with his 90%. So he decides to "skip" his turn to generate a block. The rest 10% of the network detects this and penalizes the adversary by setting his mining power to 0 and distributing it among other miners. Now the network is back to 100% power coz everyone got 10-fold increase. The adversary can mine other branch in a secret place but it won't be able to replace the legit branch. Of course, the 2nd branch will have 100% "hashing" power tied to it as well, coz the attacker will get his 90% bumped to 100% but this can be counteracted by some mechanisms of advanced consensus (still not revealed).

As a 100% PoS currency Nxt is protected against a government wealthy entity that could buy/produce a lot of ASICs, with the transparent mining it's protected even against someone buying most of the coins.

So, what does make Nxt a really next-gen currency? Not those nice features like decentralized exchange, or decentralized DNS, or decentralized app store. The transparent mining algo does, and this is only the 1st part of BCNext's plan...



This is a short description. Ask questions that will help to make the description more clear.

PS: Cunicula, BCNext is waiting for ur approval on this.

Edit: BCNext pointed out that I forgot to mention Selfish Mining. Sorry. Transparent mining solves the selfish mining issue completely. Dixi.

[1714955791]

1714955791

[1714955791]

1714955791

[1714955791]

1714955791

[1714955791]

1714955791

[1714955791]

1714955791

[1714955791]

1714955791

[NxtChoice]

with the transparent mining it's protected even against someone buying most of the coins.

Will this affect the price?

How to define "most of the coins". Of course it shoud not be 51%, so how about 5%?

[Come-from-Beyond]

I'm not sure I catch what the particular implications of that last part are. Is there a specific penalty for not mining?

Non-mining stakeholders get temporary penalty to their ability to mine.

[abctc]

Interesting plan, but does it needed to be implemented right now? It seems that Hallmarks, introduced in the v.0.3.15, can secure the Nxt for a quite long time. And maybe right now decentralized exchange (first in history) is more important for Nxt to survive against an emerging competitors.

[Come-from-Beyond]

with the transparent mining it's protected even against someone buying most of the coins.

Will this affect the price?

How to define "most of the coins". Of course it shoud not be 51%, so how about 5%?

Dunno about the price.

Most of the coins is 90%+, maybe even 99%.

[Come-from-Beyond]

Interesting plan, but does it needed to be implemented right now? It seems that Hallmarks, introduced in the v.0.3.15, can secure the Nxt for a quite long time. And maybe right now decentralized exchange (first in history) is more important for Nxt to survive against an emerging competitors.

BCNext decided to implement transparent mining step-by-step. This is more important than decentralized exchange, imo. It's like quality (mining) vs quantity (exchange).

[NxtChoice]

with the transparent mining it's protected even against someone buying most of the coins.

Will this affect the price?

How to define "most of the coins". Of course it shoud not be 51%, so how about 5%?

Dunno about the price.

Most of the coins is 90%+, maybe even 99%.

yeah, so it is an absoultely secure network. However, I care about Nxt distribution right now. How will those 5% react?

[Come-from-Beyond]

yeah, so it is an absoultely secure network. However, I care about Nxt distribution right now. How will those 5% react?

Which 5%?

[NxtChoice]

yeah, so it is an absoultely secure network. However, I care about Nxt distribution right now. How will those 5% react?

Which 5%?

Those who owns ~ 5% of the total coins.

[bizz]

I'm not sure I catch what the particular implications of that last part are. Is there a specific penalty for not mining?

Non-mining stakeholders get temporary penalty to their ability to mine.

Brilliant. So this system would introduce something like what mining pools have against pool hopping?

[Come-from-Beyond]

yeah, so it is an absoultely secure network. However, I care about Nxt distribution right now. How will those 5% react?

Which 5%?

Those who owns ~ 5% of the total coins.

If they miss their chance to mine a block they'll be penalized. Stakeholders r supposed to protect Nxt, not just sit and wait for 1 NXT = 1,000,000 USD day.

NB: The only penalty is inability to mine blocks within some period of time. They still can decide not to bother with mining, but their "hashing" power will be distributed to those who do protect the network.

[Come-from-Beyond]

I'm not sure I catch what the particular implications of that last part are. Is there a specific penalty for not mining?

Non-mining stakeholders get temporary penalty to their ability to mine.

Brilliant. So this system would introduce something like what mining pools have against pool hopping?

Sorry, I'm not familiar with pool hopping.

[bizz]

I'm not sure I catch what the particular implications of that last part are. Is there a specific penalty for not mining?

Non-mining stakeholders get temporary penalty to their ability to mine.

Brilliant. So this system would introduce something like what mining pools have against pool hopping?

Sorry, I'm not familiar with pool hopping.

Pool-hopping is the practice of mining in a pool only during the good times, and leaving during the bad times; by so doing, a pool-hopper can get more out of the pool than the value he contributes to it, increasing his rewards at the expense of other miners.

PPLNS favors constant and/or occasional loyal pool members over pool hoppers.
http://pool-x.eu/aboutpplns

Although very different because this is POS and no new coins are created it is comparable?

[Come-from-Beyond]

Although very different because this is POS and no new coins are created it is comparable?

I think no.

[NxtChoice]

NB: The only penalty is inability to mine blocks within some period of time. They still can decide not to bother with mining, but their "hashing" power will be distributed to those who do protect the network.

Due to the redistribution of "hashing power", is there any chance for someone who holds less than 50% attack the network?

Say, 50% of the coins are "dead" (never mining), the max of which holds 27% of total coins. Now the other 50% coins are mining, and the max holding of which is 26% of the total coins, will this 26% ( more than 50% of the redistribution power) attack the network? Is the network monitoring the maximum "alive power"? Hmm, very interesting, the dynamic PoS mining power network!

[NxtChoice]

yeah, so it is an absoultely secure network. However, I care about Nxt distribution right now. How will those 5% react?

Which 5%?

Those who owns ~ 5% of the total coins.

If they miss their chance to mine a block they'll be penalized. Stakeholders r supposed to protect Nxt, not just sit and wait for 1 NXT = 1,000,000 USD day.

There is still some diligent stakeholders now mining and protecting the network, so they are always richer and richer. It is different from Peercoin, which is an open and maybe a little inflation system, and the rich and poor always get richer at the same rate. But Nxt is a closed and constant coin system. It the distribution problem can't handle properly, Nxt can't get mass adoption, which does hurt the stakeholders.

[Come-from-Beyond]

NB: The only penalty is inability to mine blocks within some period of time. They still can decide not to bother with mining, but their "hashing" power will be distributed to those who do protect the network.

Due to the redistribution of "hashing power", is there any chance for someone who holds less than 50% attack the network?

Say, 50% of the coins are "dead" (never mining), the max of which holds 27% of total coins. Now the other 50% coins are mining, and the max holding of which is 26% of the total coins, will this 26% ( more than 50% of the redistribution power) attack the network? Is the network monitoring the maximum "alive power"? Hmm, very interesting, the dynamic PoS mining power network!

Mm... I lost in ur numbers.

[Come-from-Beyond]

It the distribution problem can't handle properly, Nxt can't get mass adoption, which does hurt the stakeholders.

So be it.

[klee]

It the distribution problem can't handle properly, Nxt can't get mass adoption, which does hurt the stakeholders.

So be it.

[DiCE1904]

This is great! You guys are doing an amazing job

Looking forward to the future of this coin

[Bitventurer]

Seems fair to me , but what if I'm having problems with installing the client?  or don’t want install the client for security reasons? can  I still mine with the online version?

[opticalcarrier]

only 1/7 of stakeholders were forging?

I was about to make the following comment in the regular thread:

at the very least, the stakeholders that havent distributed at good portion of their stash yet should not forge.  At least then it would give a chance to the regular blow here to forge.

At least in the beginning here, until there is a better distribution.  I know the stability and security of the network does depend on many active forgers, but come on...

but I guess its a non-issue now

[Hazard]

"Transparent" on a closed source system. Hilarious.

[opticalcarrier]

Amazing.  This is very slick. Ive linked to your thread here on nextcoin.org and stickied it over there.  

Also, can you define the term "stakeholder" as it pertains to just the topic in this post?  I kind of think what you really mean are just accounts with an inordinary high amount of NXT.  If not how can the system determine who the original stakeholders are?

What if a non-stakeholder buys 10M NXT, and has more than some stakeholders who have been distributing coins?  Will they get penalized for not forging?

How long does the system penalize a stakeholder by giving them 0 forging power to those who arent generating blocks?

[Come-from-Beyond]

"Transparent" on a closed source system. Hilarious.

I was curious how long till u find this thread. Looking forward to see ur comments after the 3rd of January.

[Come-from-Beyond]

BCNext pointed out that I forgot to mention Selfish Mining. Sorry. Transparent mining solves the selfish mining issue completely. Dixi.

[Come-from-Beyond]

Seems fair to me , but what if I'm having problems with installing the client?  or don’t want install the client for security reasons? can  I still mine with the online version?

Yes, u can.

[Come-from-Beyond]

Also, can you define the term "stakeholder" as it pertains to just the topic in this post?  I kind of think what you really mean are just accounts with an inordinary high amount of NXT.  If not how can the system determine who the original stakeholders are?

Stakeholder = anyone who owns at least 1 smallest unit of NXT.

How long does the system penalize a stakeholder by giving them 0 forging power to those who arent generating blocks?

Details r yet to be tweaked after peer review.

[msin]

Really like this idea, keep em coming!

[Gonzo418]

I think this is a great news for the nxt coin.

But am I getting things right ? For me this sounds like a "round-robin" coin generation. Everyone will get their time slice in which he's able to mine/generate coins. If his client is not open/connected to the network, network will search another node and give it the right to mine ?

[Come-from-Beyond]

I think this is a great news for the nxt coin.

But am I getting things right ? For me this sounds like a "round-robin" coin generation. Everyone will get their time slice in which he's able to mine/generate coins. If his client is not open/connected to the network, network will search another node and give it the right to mine ?

Aye, something like that.

[cheetah3]

Hi All!

I'm reading.. reading.... and I'm lost: finally they allow NXT mining or not?
And if yes, then what do I need to start mining?
Account registered, exists some small amount in wallet... What next? How to enable mining / generating nxtcoins?

Thanks!

[Come-from-Beyond]

Hi All!

I'm reading.. reading.... and I'm lost: finally they allow NXT mining or not?
And if yes, then what do I need to start mining?
Account registered, exists some small amount in wallet... What next? How to enable mining / generating nxtcoins?

Thanks!

Just leave ur account unlocked.

[bizz]

Hi All!

I'm reading.. reading.... and I'm lost: finally they allow NXT mining or not?
And if yes, then what do I need to start mining?
Account registered, exists some small amount in wallet... What next? How to enable mining / generating nxtcoins?

Thanks!

If you want to mine anything at this point you'll need to shell out at least 5-6 BTC for 1mil Nxt at current rates and then also wait for network to grow to get more fees. Just like when ASICs came to Bitcoin. It's a big risky bet but also big potential rewards.

As a plus ASIC you buy today will never rise in value while Nxt might go ballistic. Or it will crash to 0 & burn in flames.  Once again: it's one big gamble.

[Snail2]

Are there any specific memory requirements for the JVM if I wanna mine?
What ports I need to open on the firewalls?

+1
Where is the mining chapter in the howto ?

I know, I know ppl who's too stupid to find these things out by disassembling the classes and reading the code don't deserve to mine this stuff  .

[superresistant]

If you want to mine anything at this point you'll need to shell out at least 5-6 BTC for 1mil Nxt at current rates and then also wait for network to grow to get more fees. Just like when ASICs came to Bitcoin. It's a big risky bet but also big potential rewards.
As a plus ASIC you buy today will never rise in value while Nxt might go ballistic. Or it will crash to 0 & burn in flames.   Once again: it's one big gamble.

It is very likely to go ballistic in my opinion.

Are there any specific memory requirements for the JVM if I wanna mine?
What ports I need to open on the firewalls?
+1
Where is the mining chapter in the howto ?
I know, I know ppl who's too stupid to find these things out by disassembling the classes and reading the code don't deserve to mine this stuff  .

You can set the memory parameters with command line on Java
port 7874
To mine, just put coin on the wallet and stay online.

EDIT :
- 7874 (tcp) is used for P2P communication, the http web client and API commands.  This is the only port that needs to be open to run Nxt.
- 7875 (tcp) is used for the https web client.

[Snail2]

You can set the memory parameters with command line on Java
port 7875
To mine, just put coin on the wallet and stay online.

Thanks. I know how to tune the heap sized but I'm not sure if my "-Xms256m -Xmx1024m" will be good enough. Am I need to do anything with GCs or just leave all these things alone?

[opticalcarrier]

You can set the memory parameters with command line on Java
port 7875 7874
To mine, just put coin on the wallet and stay online.

Thanks. I know how to tune the heap sized but I'm not sure if my "-Xms256m -Xmx1024m" will be good enough. Am I need to do anything with GCs or just leave all these things alone?

you were just given incorrect info.  DO NOT open port 7875 on your router.  the p2p port is 7874.

the 2 of you guys should edit your posts to correct this

[User705]

Seems fair to me , but what if I'm having problems with installing the client?  or don’t want install the client for security reasons? can  I still mine with the online version?

Yes, u can.

Where is this online version?  Also is there a way to do cold storage?  I understand that means I won't generate fee coins.

[Come-from-Beyond]

Where is this online version?  Also is there a way to do cold storage?  I understand that means I won't generate fee coins.

U have to find a public server that doesn't block access. I used to provide one but now it's used to host a special version with Asset Exchange.

To store coins in cold just send them to an account that u don't use. U must send at least 1 NXT to any account from cold account to reserve ur account id.

[User705]

Where is this online version?  Also is there a way to do cold storage?  I understand that means I won't generate fee coins.

U have to find a public server that doesn't block access. I used to provide one but now it's used to host a special version with Asset Exchange.

To store coins in cold just send them to an account that u don't use. U have to send at least 1 NXT to any account though to reserve ur account id.

So generating an address can only be done by downloading the client and running it?  And once done and Nxt recieved I can erase it?  And after to retrieve coins I simply start up the new client with same pass phrase?

[Come-from-Beyond]

So generating an address can only be done by downloading the client and running it?  And once done and Nxt recieved I can erase it?  And after to retrieve coins I simply start up the new client with same pass phrase?

Yes.

[RoooooR]

Why the price is going up? I sold yesterday, now its x3 ?

[Come-from-Beyond]

Why the price is going up? I sold yesterday, now its x3 ?

Anon136 published his review of Nxt mining algo.

[RoooooR]

Why the price is going up? I sold yesterday, now its x3 ?

Anon136 published his review of Nxt mining algo.

Oh thanks.

[User705]

Does the client still mine/forge if the lock button on the account is closed or it has to stay open?

[Come-from-Beyond]

Does the client still mine/forge if the lock button on the account is closed or it has to stay open?

It has to stay open. But u can close the browser.

[User705]

Does the client still mine/forge if the lock button on the account is closed or it has to stay open?

It has to stay open. But u can close the browser.

Where can I read about the security aspects of running it this way?

[dE_logics]

The 2nd scenario can't be applied to Nxt, coz no NXTs exist outside the network.

Why?

[Come-from-Beyond]

The 2nd scenario can't be applied to Nxt, coz no NXTs exist outside the network.

Why?

Err, because no NXTs exist outside the network. Supply of NXT is limited.

[dE_logics]

The 2nd scenario can't be applied to Nxt, coz no NXTs exist outside the network.

Why?

Err, because no NXTs exist outside the network. Supply of NXT is limited.

"Outside the network", do you mean the block chain cannot be forked?

[Come-from-Beyond]

"Outside the network", do you mean the block chain cannot be forked?

I mean that unlike ASICs, that can be created by someone, noone can create NXT coins (which r like ASICs in PoS currency) and bring them into the system.

[Cryddit]

I like this about Nxt:

In order to mine, you have to invest in Nxt, not in computer hardware.  
And when you sell some amount of your Nxt for Bitcoin (or whatever), you lose that amount of your ability to mine.

So it gets the usual pump-n-dump miners coming, and going.  In order to mine, they have to support the price by buying and holding.  And when they cash out, they lose their ability to mine.  So there's no jumping in and out the way multipools usually do, and the kind of disruption that causes simply doesn't happen.

It's also less unfair than the usual mining setup because it doesn't reward centralization.  If you some amount in mining Nxt, you get the same mining power per money invested as someone who invests any other amount in Nxt, where with most PoW coins you get substantially more than a fair share of blocks as you invest more money.

I like these features, but I bet P&D miners just hate 'em.  In fact, without the enthusiastic support of the "early miner" crowd, I wonder how nxt has even gotten past launch.

[Cryddit]

Of course, I dislike this about Nxt: 

Closed source code.  I like the mining algorithm, but absolutely cannot run closed-source from someone who would be hard to sue, for anything that involves a substantial amount of money. 

[dE_logics]

"Outside the network", do you mean the block chain cannot be forked?

I mean that unlike ASICs, that can be created by someone, noone can create NXT coins (which r like ASICs in PoS currency) and bring them into the system.

But we were talking about 51% attacks here. You mean the mining system is such that the block chain cannot be forked?

[Come-from-Beyond]

Of course, I dislike this about Nxt: 

Closed source code.  I like the mining algorithm, but absolutely cannot run closed-source from someone who would be hard to sue, for anything that involves a substantial amount of money. 

There are a lot of Java programmers on this board. Ask any and they will disassemble .class files, the files r not obfuscated. Ppl who say that Java binaries is closed source understand nothing in Java (well, they shouldn't).

[dE_logics]

I like these features, but I bet P&D miners just hate 'em.  In fact, without the enthusiastic support of the "early miner" crowd, I wonder how nxt has even gotten past launch.

I wouldn't like to comment on this before understanding the coin but --

dgex.com

How do you prove the authenticity of this site?

It maybe that the NXT author just inflated the prices (cause he's also owning the website) and took BTC for a crypto which has no value.

[Come-from-Beyond]

But we were talking about 51% attacks here. You mean the mining system is such that the block chain cannot be forked?

Ah, sorry, lost myself.

With transparent mining we should talk about 90% attack. 51% attack can't be conducted coz the other 49% will stick to "legit" chain. I wish I could explain this but my English is too little for that.

[User705]

"Outside the network", do you mean the block chain cannot be forked?

I mean that unlike ASICs, that can be created by someone, noone can create NXT coins (which r like ASICs in PoS currency) and bring them into the system.

But we were talking about 51% attacks here. You mean the mining system is such that the block chain cannot be forked?

Mining and owning BTC are two separate activities.  In Nxt they are not.  Assuming Nxt works as advertised double spends appear to be impossible.

[dE_logics]

"Outside the network", do you mean the block chain cannot be forked?

I mean that unlike ASICs, that can be created by someone, noone can create NXT coins (which r like ASICs in PoS currency) and bring them into the system.

You mean there's no incentive to fork the chain?

Remember, original question is the meaning of "Outside the network".

[dE_logics]

"Outside the network", do you mean the block chain cannot be forked?

I mean that unlike ASICs, that can be created by someone, noone can create NXT coins (which r like ASICs in PoS currency) and bring them into the system.

But we were talking about 51% attacks here. You mean the mining system is such that the block chain cannot be forked?

Mining and owning BTC are two separate activities.  In Nxt they are not.  Assuming Nxt works as advertised double spends appear to be impossible.

See the question is how. Assuming an attack is 91%; suppose someone owns 95% coins, how will he not be able to create a forked chain which double spends coins?

[dE_logics]

Also can you explain 'base target'?

[User705]

"Outside the network", do you mean the block chain cannot be forked?

I mean that unlike ASICs, that can be created by someone, noone can create NXT coins (which r like ASICs in PoS currency) and bring them into the system.

But we were talking about 51% attacks here. You mean the mining system is such that the block chain cannot be forked?

Mining and owning BTC are two separate activities.  In Nxt they are not.  Assuming Nxt works as advertised double spends appear to be impossible.

See the question is how. Assuming an attack is 91%; suppose someone owns 95% coins, how will he not be able to create a forked chain which double spends coins?

If he spends them how will he mine the next blocks?

[dE_logics]

"Outside the network", do you mean the block chain cannot be forked?

I mean that unlike ASICs, that can be created by someone, noone can create NXT coins (which r like ASICs in PoS currency) and bring them into the system.

But we were talking about 51% attacks here. You mean the mining system is such that the block chain cannot be forked?

Mining and owning BTC are two separate activities.  In Nxt they are not.  Assuming Nxt works as advertised double spends appear to be impossible.

See the question is how. Assuming an attack is 91%; suppose someone owns 95% coins, how will he not be able to create a forked chain which double spends coins?

If he spends them how will he mine the next blocks?

He'll not spend them, he'll hold them and use to create a forked block chain with false transactions (double spending the transactions which resulted in 95% of coins being with him).

[User705]

Perhaps CfB can give an answer to that question.  I don't see how you can make a double spend with pure PoS but I'm no expert.

[Come-from-Beyond]

See the question is how. Assuming an attack is 91%; suppose someone owns 95% coins, how will he not be able to create a forked chain which double spends coins?

He will be able to do that.

PS: I can't get what the problem with "Outside the network". Could u paraphrase the question, please?

[dE_logics]

See the question is how. Assuming an attack is 91%; suppose someone owns 95% coins, how will he not be able to create a forked chain which double spends coins?

He will be able to do that.

PS: I can't get what the problem with "Outside the network". Could u paraphrase the question, please?

You said --

The 2nd scenario can't be applied to Nxt, coz no NXTs exist outside the network. Let's look closer at the 1st scenario.

The 2nd scenario can be applied by someone possessing 91% or more of coins; this's similar to having a lot of 'mining equipment' or tools to mine coins. For Bitcoins it's ASIC miners, for Litecoins it's the graphics cards, for Quarks it's the CPU and for for PPcoin and NXT it's the currency themselves.

[dE_logics]

Perhaps CfB can give an answer to that question.  I don't see how you can make a double spend with pure PoS but I'm no expert.

Oh, yes you can. And it's not that hard (for regular PoS coins, not this one).

You need to run a full node in order for the wallet to mine blocks based on PoS and it should be up always; how many people will do that? (especially when the interest rate is low)? When these coins will be made popular, 90% people will run paper wallets giving power to the hands of these 10%; thus an attack may not be that hard to do.

[Come-from-Beyond]

See the question is how. Assuming an attack is 91%; suppose someone owns 95% coins, how will he not be able to create a forked chain which double spends coins?

He will be able to do that.

PS: I can't get what the problem with "Outside the network". Could u paraphrase the question, please?

You said --

The 2nd scenario can't be applied to Nxt, coz no NXTs exist outside the network. Let's look closer at the 1st scenario.

The 2nd scenario can be applied by someone possessing 91% or more of coins; this's similar to having a lot of 'mining equipment' or tools to mine coins. For Bitcoins it's ASIC miners, for Litecoins it's the graphics cards, for Quarks it's the CPU and for for PPcoin and NXT it's the currency themselves.

I meant that unlike Bitcoin et all. noone could bring extra mining power from outside.

[2Kool4Skewl]

It would be very difficult to obtain over 90% of Nxt.  No more Nxt will ever be created and not very many people are selling.

[dE_logics]

I know.

I was just clarifying.

So let's move on to the next question.

[dE_logics]

Also can you explain 'base target'?

[Come-from-Beyond]

Also can you explain 'base target'?

Base target is a quotient that shows current difficulty. Each miners has a target that equals to BaseTarget*Balance.

[dE_logics]

Also can you explain 'base target'?

Base target is a quotient that shows current difficulty. Each miners has a target that equals to BaseTarget*Balance.

So the incentive to mining blocks is the transaction fee.

Like with regular PoS, the more coins you hold for a longer period, the more the chance of mining a block.

[Come-from-Beyond]

Like with regular PoS, the more coins you hold for a longer period, the more the chance of mining a block.

No. Ur algo is flawed. BCNext used other algo.

[dE_logics]

Like with regular PoS, the more coins you hold for a longer period, the more the chance of mining a block.

No. Ur algo is flawed. BCNext used other algo.

Then can someone please explain?

[Come-from-Beyond]

Then can someone please explain?

Ur chance to forge a block depends on BaseTarget (which is the same for all), TimeSinceLastBlock (which is the same for all) and ur account balance:

Code:

Chance = BaseTarget * TimeSinceLastBlock * Balance

[dE_logics]

Then can someone please explain?

Ur chance to forge a block depends on BaseTarget (which is the same for all), TimeSinceLastBlock (which is the same for all) and ur account balance:

Code:

Chance = BaseTarget * TimeSinceLastBlock * Balance

Ok, it does not depend on how long you old the coins.

On what basis will the difficulty increase? May large holders of the coin?

[Cryddit]

The difficulty would just need to be proportional to the number of coins being used for mining.  Anyway, it doesn't probably need to adjust more than once per a long enough period for the money supply to change significantly.  The description is that the factor due to time since the last block is exponential - ie, it doubles once a minute or something like that.  So even if there's twice as many coins being used for mining, block times only get one minute shorter.   And even if 75% of the coins used for mining are taken offline, the block times would get only two minutes longer. 

There's probably no real need for difficulty to change more often than new versions of the client come out.  That said, there may be a feedback mechanism that does the difficulty changes built-in, but I wouldn't worry if there isn't.

[dE_logics]

Thanks for the explanation.

Yesterday the average base target was ~700%. This means that only 1/7 of all stakeholders were generating blocks, we can't say if the rest 6/7 were hit by bus or trying to fork Nxt blockchain.

This means that with increasing difficulty, instead of reducing the probability of the low valued stake holders to mine blocks, the algorithm cuts off their chance of mining the blocks completely. Now with difficulty 700% (e.g.), only 1/7th of the total coin holders who have the maximum held coins will be able to generate a block. The algorithm cuts out the 6/7th cause they don't have enough balance.

The list of the top 1/7th holder of coins can be generated and so the future miner of the block can be predicted.

Is this correct?

[Come-from-Beyond]

Is this correct?

No. Nxt forging works the same way as Bitcoin does. U can mine a block even with CPU, chance is very low, but reward is very high. In the long run everyone will get exactly the same ROI.

[opticalcarrier]

not sure if this has been asked, but if transparent miing allows the network to know who will generate the next block, then what is to keep our adversary from also finding out who it is and then DDOSing the ever living hell out that client?

[Come-from-Beyond]

not sure if this has been asked, but if transparent miing allows the network to know who will generate the next block, then what is to keep our adversary from also finding out who it is and then DDOSing the ever living hell out that client?

If a forging node can't handle much traffic it can forge behind Tor.

[Cryddit]

not sure if this has been asked, but if transparent miing allows the network to know who will generate the next block, then what is to keep our adversary from also finding out who it is and then DDOSing the ever living hell out that client?

If a forging node can't handle much traffic it can forge behind Tor.

Ohh, that's one of the wrong answers.  That's just saying "not my problem" which means you have no solution.  I was actually thinking this would work until you failed to answer that.

[Come-from-Beyond]

not sure if this has been asked, but if transparent miing allows the network to know who will generate the next block, then what is to keep our adversary from also finding out who it is and then DDOSing the ever living hell out that client?

If a forging node can't handle much traffic it can forge behind Tor.

Ohh, that's one of the wrong answers.  That's just saying "not my problem" which means you have no solution.  I was actually thinking this would work until you failed to answer that.

I know that u just trolling. Welcome to the box with other trolls.

[virtualaddict]

Nxt just flew passed Mastercoin's marketcap 

As I understand it, the difference in function between Mastercoin and Nxt is that Mastercoin requires BTC to function whereas Nxt could replace BTC entirely.

[xibeijan]

"Outside the network", do you mean the block chain cannot be forked?

I mean that unlike ASICs, that can be created by someone, noone can create NXT coins (which r like ASICs in PoS currency) and bring them into the system.

I think the question is:

What happens if someone has the NXT source code, creates a new genesis block and creates and entirely new NXT network, with an entirely new supply of NXT (on this second network), with a completely new block chain that is longer than the NXT one, then joins the NXT network?

[Come-from-Beyond]

What happens if someone has the NXT source code, creates a new genesis block and creates and entirely new NXT network, with an entirely new supply of NXT (on this second network), with a completely new block chain that is longer than the NXT one, then joins the NXT network?

Nothing. He won't be able to catch the blocks nor able to push his own blocks/transactions.

[mczarnek]

So it's closed source but as someone pointed out, it is possible to decompile that.

But as I understand it, individual 'miners' take turns approving transactions, so what prevents people from making it so that every time it is their turn to mine, they transfer coins from a wallet that doesn't belong to them to their own wallet and then approve the transaction?

Also, what kind of speed is there for confirmation time?  If you could beat litecoin's transaction time..  I think that alone would be a reason everyone would turn to Nextcoin and seems possibly doable given the unique mining system.

[Come-from-Beyond]

So it's closed source but as someone pointed out, it is possible to decompile that.

Aye.

But as I understand it, individual 'miners' take turns approving transactions, so what prevents people from making it so that every time it is their turn to mine, they transfer coins from a wallet that doesn't belong to them to their own wallet and then approve the transaction?

It's impossible to take coins from someone else wallet.

Also, what kind of speed is there for confirmation time?  If you could beat litecoin's transaction time..  I think that alone would be a reason everyone would turn to Nextcoin and seems possibly doable given the unique mining system.

1 min between blocks.

[mczarnek]

It's impossible to take coins from someone else wallet.

What makes it impossible?  I guess we simply won't know until the source code is released, at which point I could see someone hacking it, but sounded to me like for each transaction, potentially only one person could be confirming the transaction at a time.  If you are the only one confirming and have shady motives what prevents you from inserting fake transactions?


Still wish it was faster.. I liked a 5 second block because I want a coin that can be used for grocery store transactions with confirmation which doesn't require waiting for a minute for checkout but still very nice regarding 1 min block!  At least it's more than double litecoin's speed.

[opticalcarrier]

1 min between blocks.

what mechanism is it that causes the timing to drift? sometimes there are blocks every few seconds, sometimes every 15 mins, etc.

[Vega]

1 min between blocks.

what mechanism is it that causes the timing to drift? sometimes there are blocks every few seconds, sometimes every 15 mins, etc.

Yeah, I wanted to ask this for a while. The avarage blocks per day are somewhere below 800. Why is that?

[mczarnek]

Also this post is talking about instant transaction mode: https://bitcointalk.org/index.php?topic=347927.0

Could you tell me how that works?  Thanks!

[Come-from-Beyond]

What makes it impossible?  I guess we simply won't know until the source code is released, at which point I could see someone hacking it, but sounded to me like for each transaction, potentially only one person could be confirming the transaction at a time.  If you are the only one confirming and have shady motives what prevents you from inserting fake transactions?


Still wish it was faster.. I liked a 5 second block because I want a coin that can be used for grocery store transactions with confirmation which doesn't require waiting for a minute for checkout but still very nice regarding 1 min block!  At least it's more than double litecoin's speed.

Sorry, I don't have time to tell u basic things. U should read more about Cryptography and Bitcoin, and then we'll continue the discussion. Ok?

[Come-from-Beyond]

1 min between blocks.

what mechanism is it that causes the timing to drift? sometimes there are blocks every few seconds, sometimes every 15 mins, etc.

Yeah, I wanted to ask this for a while. The avarage blocks per day are somewhere below 800. Why is that?

Timing drifts due to stochastic nature of forging. Average blocks per day is below 800 coz of high rate of orphaned blocks.

[Come-from-Beyond]

Also this post is talking about instant transaction mode: https://bitcointalk.org/index.php?topic=347927.0

Could you tell me how that works?  Thanks!

https://bitcointalk.org/index.php?topic=316104.0

[mczarnek]

Thanks Come-from-Beyond..  yeah, reading as fast as I can about this stuff, just got into the game a couple weeks ago.  probably time to focus some energy on understanding how the actual low-level hashing works.  I'm definitely going to jump into the code when released and see if I can figure it out.

One more quick question though, as I understand it, it is possible to predict which machine(s) will be be forging the next block.  Once you know, you can DDOS them, which seems like it could cause big problems.  How much of a risk is that?

[Come-from-Beyond]

One more quick question though, as I understand it, it is possible to predict which machine(s) will be be forging the next block.  Once you know, you can DDOS them, which seems like it could cause big problems.  How much of a risk is that?

CloudFlare solves this problem. U can forge using 5y-old notebook, all the traffic will be handled by 3rd party if u can't do it by urself.

[Jimmy2011]

TF has been enabled about one day ago, but it seems that no real different from the older version from the client, of course I think the core in the client may be TF functionable. So for the average joe, how can we get some hint on TF which is working?

[Come-from-Beyond]

TF has been enabled about one day ago, but it seems that no real different from the older version from the client, of course I think the core in the client may be TF functionable. So for the average joe, how can we get some hint on TF which is working?

This is partial migration.

[bitcoinpaul]

If they miss their chance to mine a block they'll be penalized. Stakeholders r supposed to protect Nxt, not just sit and wait for 1 NXT = 1,000,000 USD day.

NB: The only penalty is inability to mine blocks within some period of time. They still can decide not to bother with mining, but their "hashing" power will be distributed to those who do protect the network.

When will this penalty be implemented?

[Come-from-Beyond]

If they miss their chance to mine a block they'll be penalized. Stakeholders r supposed to protect Nxt, not just sit and wait for 1 NXT = 1,000,000 USD day.

NB: The only penalty is inability to mine blocks within some period of time. They still can decide not to bother with mining, but their "hashing" power will be distributed to those who do protect the network.

When will this penalty be implemented?

No ETA yet.

[bitcoinpaul]

thx

[allwelder]

understand some little.

[coradan]

There is an issue in the "transparent mining" that I can not see clearly: if someone hides an alternative chain, how does it identify what is the good branch and what is bad. I can not find the formula to do possible this identification...

The only thing I can think is that the two chains evolve by its side, both with their private 100% of the currency involved in the generation of each block, and it would be possible setting one fork or more of the network...  Let we can say that the network is protected of attacks, but not for forks.  I dont know what is worst...

Maybe I have not the data which is measured to determine the valid chain, I dont know if it is the greatest amount of currency, coin-age, or what...

You said: "this can be counteracted by some mechanisms of advanced consensus..."  But I thing that in the moment that we talk about consensus, we have the 51% problem over the table again...

[opticalcarrier]

...You said: "this can be counteracted by some mechanisms of advanced consensus..."  But I thing that in the moment that we talk about consensus, we have the 51% problem over the table again...

Yes, when will we hear more of this?  It seems if it is not addressed then there is a risk?  what is the state of things in this regard now?

[Come-from-Beyond]

...You said: "this can be counteracted by some mechanisms of advanced consensus..."  But I thing that in the moment that we talk about consensus, we have the 51% problem over the table again...

Yes, when will we hear more of this?  It seems if it is not addressed then there is a risk?  what is the state of things in this regard now?

Every node is supposed to stick to a branch where his balance is higher. Extended consensus will be described in other parts of the plan, we have to wait.

[geekz]

NXT is not fungible. The most basic feature required for any currency.
Bitcoin is fungible to millionth.

[coradan]

I think the 51% attack is possible in PoS with or without "transparent mining", the advantage is that in PoS it is less likely than PoW...

[Come-from-Beyond]

NXT is not fungible. The most basic feature required for any currency.
Bitcoin is fungible to millionth.

 

[Come-from-Beyond]

I think the 51% attack is possible in PoS with or without "transparent mining", the advantage is that in PoS it is less likely than PoW...

Let's wait for the full disclosure of Transparent Mining.

[geekz]

NXT is not fungible. The most basic feature required for any currency.
Bitcoin is fungible to millionth.

 

Can you send someone 0.001 NXTCOINS?

[coradan]

I think the 51% attack is possible in PoS with or without "transparent mining", the advantage is that in PoS it is less likely than PoW...

Let's wait for the full disclosure of Transparent Mining.

I will wait, but the forks are an important problem in transparent mining...  

[Come-from-Beyond]

Can you send someone 0.001 NXTCOINS?

No. But it will be possible in a couple of months.

[geekz]

Can you send someone 0.001 NXTCOINS?

No. But it will be possible in a couple of months.

Biggest scamcoin of all time.

[Come-from-Beyond]

Biggest scamcoin of all time.

Where do u all guys come from? I'm even tired to repeat:

- Thank u for ur competent opinion.

[geekz]

Can you send someone 0.001 NXTCOINS?

No. But it will be possible in a couple of months.

Someone sent me some nxtcoins. I see it under my transactions. But the balance is still zero.
I did only one transaction , it shows the same thing 3 times.
It has got so many problems.

[geekz]

How did you had an exchange ready even before releasing the coin??

[opticalcarrier]

it wasnt up until a week or so after genesis block

[Digicoiner]

If I have to close my client each night for example how long will I get a "temporary penalty" to mine - a few minutes, hours?  I'm worried that closing the client at night will nullify my ability to mine the next day.

[Come-from-Beyond]

If I have to close my client each night for example how long will I get a "temporary penalty" to mine - a few minutes, hours?  I'm worried that closing the client at night will nullify my ability to mine the next day.

1440 blocks in current design.

[DiCE1904]

If I have to close my client each night for example how long will I get a "temporary penalty" to mine - a few minutes, hours?  I'm worried that closing the client at night will nullify my ability to mine the next day.

Good question, I had the same question. Thanks for addressing it CfB

[Digicoiner]

If I have to close my client each night for example how long will I get a "temporary penalty" to mine - a few minutes, hours?  I'm worried that closing the client at night will nullify my ability to mine the next day.

1440 blocks in current design.

So if the temporary penalty to mine is 1440 blocks (24 hours) due having an account offline then it's not really worth it (in terms of forging) to bring the account online each morning as it will never surpass the penalty time.  This might be the situation for some people who want to forge.

[subSTRATA]

To store coins in cold just send them to an account that u don't use. U must send at least 1 NXT to any account from cold account to reserve ur account id.

What if I don't send any NXT to some other address but create 1 or more aliases, does that count as ID-reserving transaction(s)?

[opticalcarrier]

To store coins in cold just send them to an account that u don't use. U must send at least 1 NXT to any account from cold account to reserve ur account id.

What if I don't send any NXT to some other address but create 1 or more aliases, does that count as ID-reserving transaction(s)?

yes, anything that causes you to spend NXT would generate a public key on the blockchain

[BitAddict]

If I have to close my client each night for example how long will I get a "temporary penalty" to mine - a few minutes, hours?  I'm worried that closing the client at night will nullify my ability to mine the next day.

1440 blocks in current design.

No way. I forged some blocks just minutes/few hours after I reconnected the PC after closing it all the night.

I think he is speaking about the penalty when you send NxT to a new account.
Closing and opening client has no penalty.

[Come-from-Beyond]

So if the temporary penalty to mine is 1440 blocks (24 hours) due having an account offline then it's not really worth it (in terms of forging) to bring the account online each morning as it will never surpass the penalty time.  This might be the situation for some people who want to forge.

Such people will lease their forging power to "pools".

[Come-from-Beyond]

No way. I forged some blocks just minutes/few hours after I reconnected the PC after closing it all the night.

I think he is speaking about the penalty when you send NxT to a new account.
Closing and opening client has no penalty.

If u miss ur turn to forge a block u'll be penalized.

[BitAddict]

No way. I forged some blocks just minutes/few hours after I reconnected the PC after closing it all the night.

I think he is speaking about the penalty when you send NxT to a new account.
Closing and opening client has no penalty.

If u miss ur turn to forge a block u'll be penalized.

I didn't know about that :/
So it will be added in the future with TF

[ZeroTheGreat]

Can you send someone 0.001 NXTCOINS?

No. But it will be possible in a couple of months.

4 digits planned? Or variable?

No way. I forged some blocks just minutes/few hours after I reconnected the PC after closing it all the night.

I think he is speaking about the penalty when you send NxT to a new account.
Closing and opening client has no penalty.

If u miss ur turn to forge a block u'll be penalized.

Mmm, 99.9999%-to-forge-next-block-target = "your turn" or something like this? And lowforgers'll extremely rare could be penalized in that case (almost never catch up to 90%+ before shutting down)?

[Come-from-Beyond]

4 digits planned? Or variable?

No idea yet.

Mmm, 99.9999%-to-forge-next-block-target = "your turn" or something like this? And lowforgers'll extremely rare could be penalized in that case (almost never catch up to 90%+ before shutting down)?

What do u mean?

[ZeroTheGreat]

I think, I understood. There'll be multiple 100%+ chances to forge a block for many different forgers at differernt timestamps in future, but network topology + forks'es successes'll decide a winner. Right?

And if winner'll be same forger as predicted at first place (predicted for sender), TF'll get 1 confirmation to last unconfirmed txs almost instantly. If not, senders'll have to wait some more time rebroadcasting.

[Come-from-Beyond]

I think, I understood. There'll be multiple 100%+ chances to forge a block for many different forgers at differernt timestamps in future, but network topology + forks'es successes'll decide a winner. Right?

And if winner''ll be same forger as predicted at first place, TF'll get 1 confirmation to last unconfirmed txs almost instantly. If not, senders'll have to wait some more time rebroadcasting.

Aye

[opticalcarrier]

with transparent forging, could a block forger choose to not send ANY transactions except its own, a block chock full of only his own transactions, and do so for free while completely ignoring everyone elses transactions?

[starik69]

I think yes, but he also can include other unconfirmed transactions and get their fees. Why ignore money?

[opticalcarrier]

just do be a dick.  we all know people like. that.  network disruption

[Come-from-Beyond]

with transparent forging, could a block forger choose to not send ANY transactions except its own, a block chock full of only his own transactions, and do so for free while completely ignoring everyone elses transactions?

Yes, feel free to include only ur own transactions or none at all.

[opticalcarrier]

with transparent forging, could a block forger choose to not send ANY transactions except its own, a block chock full of only his own transactions, and do so for free while completely ignoring everyone elses transactions?

Yes, feel free to include only ur own transactions or none at all.

am I the only one who doesnt like this?

[martismartis]

dumb question:

Can I forge a block,when port 7874 is closed on my router?

[Come-from-Beyond]

with transparent forging, could a block forger choose to not send ANY transactions except its own, a block chock full of only his own transactions, and do so for free while completely ignoring everyone elses transactions?

Yes, feel free to include only ur own transactions or none at all.

am I the only one who doesnt like this?

The secret is that in the future each block will be forged by 2-3 accounts and they will have to compete. U will notice that ur blocks become orphaned too often if u include only ur transactions.

[starik69]

dumb question:

Can I forge a block,when port 7874 is closed on my router?

I am successfully forging behind NAT and rooter without any port forwarding. Dunno if port is specially closed.

[opticalcarrier]

dumb question:

Can I forge a block,when port 7874 is closed on my router?

I am successfully forging behind NAT and rooter without any port forwarding. Dunno if port is specially closed.

I wouldnt see why it would specifically be open.  all this means is that no peers can create connections to you - all connections you have are ones that you originate, first out to your wellknownpeers, and then to the peers they tell you about.

[martismartis]

Another dumb question with video:

http://www.youtube.com/watch?v=w1FTzBjy_8Q

Is it EXACTLY how forging works?

[starik69]

dumb question:

Can I forge a block,when port 7874 is closed on my router?

I am successfully forging behind NAT and rooter without any port forwarding. Dunno if port is specially closed.

I wouldnt see why it would specifically be open.  all this means is that no peers can create connections to you - all connections you have are ones that you originate, first out to your wellknownpeers, and then to the peers they tell you about.

Yes, i think if you can connect to others 7874 port then you can forge.

Is it EXACTLY how forging works?

Well, yes, but of course that presentation is somewhat simplified and there are more technical details.

[martismartis]

dumb question:

Can I forge a block,when port 7874 is closed on my router?

I am successfully forging behind NAT and rooter without any port forwarding. Dunno if port is specially closed.

I wouldnt see why it would specifically be open.  all this means is that no peers can create connections to you - all connections you have are ones that you originate, first out to your wellknownpeers, and then to the peers they tell you about.

Yes, i think if you can connect to others 7874 port then you can forge.

Is it EXACTLY how forging works?

Well, yes, but of course that presentation is somewhat simplified and there are more technical details.

Starik, could please check your configuration of port 7874 at http://www.yougetsignal.com/tools/open-ports/ ? Is it closed or open?

Regarding video, I think it is not correct, how forging is working in real. I'm trying to understand this video as simple Joe, but in reality I have, it is not exactly, as it showed in video. Am i wrong?

[starik69]

Starik, could please check your configuration of port 7874 at http://www.yougetsignal.com/tools/open-ports/ ? Is it closed or open?

I have a somewhat complicated setup of comps now, but be sure last month i did several tests with exact this online tool and could forge with 7874 port reported closed.

Regarding video, I think it is not correct, how forging is working in real. I'm trying to understand this video as simple Joe, but in reality I have, it is not exactly, as it showed in video. Am i wrong?

What exactly you think is wrong?

[martismartis]

Starik, could please check your configuration of port 7874 at http://www.yougetsignal.com/tools/open-ports/ ? Is it closed or open?

I have a somewhat complicated setup of comps now, but be sure last month i did several tests with exact this online tool and could forge with 7874 port reported closed.

Regarding video, I think it is not correct, how forging is working in real. I'm trying to understand this video as simple Joe, but in reality I have, it is not exactly, as it showed in video. Am i wrong?

What exactly you think is wrong?

Principle of forging.

[starik69]

Principle of forging.

That forged NXT are proportional to stake?

[martismartis]

Principle of forging.

That forged NXT are proportional to stake?

Ok, I'll try to explain how simple Joe understands this video:

Simple Joe understands, that forging is proportional to stake, there is no question. But according video, Joe sees that it is like some "queue". Joe has 10000 of NXT and waits for time to forge, after bigger stakes forge their own blocks. His in "queue". And after N blocks cames Joe time to forge. And he 100% forges a block. Right?

Sorry for my bad English.

[salsacz]

Principle of forging.

That forged NXT are proportional to stake?

Ok, I'll try to explain how simple Joe understands this video:

Simple Joe understands, that forging is proportional to stake, there is no question. But according video, Joe sees that it is like some "queue". Joe has 10000 of NXT and waits for time to forge, after bigger stakes forge their own blocks. His in "queue". And after N blocks cames Joe time to forge. And he 100% forges a block. Right?

Sorry for my bad English.

Those 4 guys represent a group of people who own different stakes. It means mostly money go to the group of people who own 3 mega. Everyone is in a qur. Rich people have shorter que than poor users

[opticalcarrier]

Principle of forging.

That forged NXT are proportional to stake?

Ok, I'll try to explain how simple Joe understands this video:

Simple Joe understands, that forging is proportional to stake, there is no question. But according video, Joe sees that it is like some "queue". Joe has 10000 of NXT and waits for time to forge, after bigger stakes forge their own blocks. His in "queue". And after N blocks cames Joe time to forge. And he 100% forges a block. Right?

Sorry for my bad English.

Those 4 guys represent a group of people who own different stakes. It means mostly money go to the group of people who own 3 mega. Everyone is in a qur. Rich people have shorter que than poor users

another way to put it is that if your account has 1000 NXT in it, if you run it continuously then it will forge approximately 1000/1000000000 of all blocks (which may/may not have transactions/fees in them).  Actually the chances will be a better than that (replace that 1 billion denominator with the total of all NXT that is forging at the moment, yes, very hard to calculate that)

[martismartis]

Principle of forging.

That forged NXT are proportional to stake?

Ok, I'll try to explain how simple Joe understands this video:

Simple Joe understands, that forging is proportional to stake, there is no question. But according video, Joe sees that it is like some "queue". Joe has 10000 of NXT and waits for time to forge, after bigger stakes forge their own blocks. His in "queue". And after N blocks cames Joe time to forge. And he 100% forges a block. Right?

Sorry for my bad English.

Those 4 guys represent a group of people who own different stakes. It means mostly money go to the group of people who own 3 mega. Everyone is in a qur. Rich people have shorter que than poor users

Ok, back to reality now. So, it is some kind of "queue", also Salsacz confirm, bigger stack- shorter "queue". Now lets go to Joe. Joe waited waited and finally here it come his time to forge. He gets his chance and instead of forging he gets "generating and incorrect block... What is this?

1) bug in software;
2) bug in Joe PC configuration;
3) this is algorythm and it should be like this, cool down Joe
4) it was lottery ticket, but unlucky;
5) ...

P.S. in one month period, joe was running newest version of server and client 24/7 and got 30-40 times this error only, no block forged. Stake is around 31000 NXT.

[ZeroTheGreat]

3)

Not queue, chances.

Do the math: how many hundreds of millions of NXT're regularly forging, how many blocks u'd expect to forge in month with 31k of NXT. Don't forget dispersion.

[jettico]

A society stratification is injected into the transparent forging as is described in wiki here http://wiki.nxtcrypto.org/wiki/Transparent_Forging .

Rich people get richer faster than poor people.

For example, a wallet with 100k coins is 199 times more likely to forge a block than a wallet with 1k coins (instead of 100 as expected).

This is bad because:
1) makes forging in pools more profitable than forging alone - less decentralization
2) makes NXT less attractive for newcomers who don't have large amounts of coins yet
3) it contradicts to what is stated in this page: http://www.nxtcrypto.org/nxt-coin/more-nxt-proof-stake-forging

Here's a python script that demonstrates the issue:

import random

NBLOCKS = 1000000
W1 = 1000
W2 = 100000

na = nb = 0.

for x in xrange(NBLOCKS):
    a = random.uniform(0, 1./W1)
    b = random.uniform(0, 1./W2)

    if a<b:
        na += 1
    elif a>b:
        nb += 1

print nb/na

200.369311317

(instead of 100 as expected)

Russian:
B aлгopитм TF зaлoжeнo paccлoeниe oбщecтвa. Бoгaтыe бoгaтeют быcтpee чeм бeдныe.

Haпpимep, кoшeлeк c 100k мoнeт гeнepиpyeт блoк c вepoятнocтью в 199 paз бoльшeй, чeм кoшeлeк c 1k мoнeт.

Boт тyт ecть вывoд фopмyлы пo-pyccки c пpимepoм кoдa, кoтopый paccлoeниe этo ycтpaняeт:

https://bitcointalk.org/index.php?topic=438479.msg4820620#msg4820620

[jettico]

A bit more details:

Steps 3-5 in http://wiki.nxtcrypto.org/wiki/Transparent_Forging from the statistics point of view are equivalent to comparing random numbers uniformly distributed between 0 and 1/N where N is number of coins in the wallet (normalization coefficient is the same for all wallets and is omitted for clarity).

Now imagine that you throw a dice with numbers from 1 to 6 and your opponent throws a semi-dice with three possible values from 1 to 3. Who gets the lower number wins the round. In half of the cases you will throw 4-6 and win. In the other half you will have 50:50 chances to win. Thus your chances are 1/2 + 1/4 = 0.75 and his chances are 1/4 = 0.25. Which is 3 times lower.

For arbitrary ratio K between two wallets the probability ratio is 2K-1. For example, a wallet with 100k coins is 199 times more likely to forge a block than 1k wallet.

For three wallets the situation is even worse: if they have coins in the proportion of 100:1:1 the probability of forging a block is 298:1:1.

And here is the code that solves the issue:

from random import random
from math import log

NBLOCKS = 1000000
W1 = 1000
W2 = 100000

na = nb = 0.

for x in xrange(NBLOCKS):
    a = log(random())/log(1-1./W1)
    b = log(random())/log(1-1./W2)

    if a>b:
        na += 1
    elif a<b:
        nb += 1

print nb/na

99.9183570491

[Come-from-Beyond]

Now imagine that you throw a dice with numbers from 1 to 6 and your opponent throws a semi-dice with three possible values from 1 to 3. Who gets the lower number wins the round. In half of the cases you will throw 4-6 and win. In the other half you will have 50:50 chances to win. Thus your chances are 1/2 + 1/4 = 0.75 and his chances are 1/4 = 0.25. Which is 3 times lower.

This doesn't model forging process correctly.

[jettico]

Reason? In the previous post I provided a python scrypt that does EXACTLY what is stated in this wiki page. http://wiki.nxtcrypto.org/wiki/Transparent_Forging

The analogy with throwing dice is for illustrative purposes only.

[sepehr]

I receive this every time it wants to initiate a block creation:

[2014-01-31 00:24:53.195] DEBUG: Error in block generation thread
java.lang.NullPointerException
        at Nxt$Block.getLastBlocks(Nxt.java:1353)
        at Nxt$Account.getGuaranteedBalance(Nxt.java:579)
        at Nxt$Account.getEffectiveBalance(Nxt.java:516)
        at Nxt$8.run(Nxt.java:6574)
        at java.util.concurrent.Executors$RunnableAdapter.call(Unknown Source)
        at java.util.concurrent.FutureTask.runAndReset(Unknown Source)
        at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.
access$301(Unknown Source)
        at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.
run(Unknown Source)
        at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
        at java.lang.Thread.run(Unknown Source)

Any Idea why this happen?

[Come-from-Beyond]

The analogy with throwing dice is for illustrative purposes only.

This is the problem. 100K account does have advantage over 100x 1K accounts. But this advantage is small. In ur example it's noticeable coz u use conventional dice. If u used dice with 2^64 faces u would get other results.

[Cryddit]

Now imagine that you throw a dice with numbers from 1 to 6 and your opponent throws a semi-dice with three possible values from 1 to 3. Who gets the lower number wins the round. In half of the cases you will throw 4-6 and win. In the other half you will have 50:50 chances to win. Thus your chances are 1/2 + 1/4 = 0.75 and his chances are 1/4 = 0.25. Which is 3 times lower.

This doesn't model forging process correctly.

I think all are agreed that the presented model is not the right way to do it.  But does it accurately state the forging process that the current code implements?

[Cryddit]

The analogy with throwing dice is for illustrative purposes only.

This is the problem. 100K account does have advantage over 100x 1K accounts. But this advantage is small. In ur example it's noticeable coz u use conventional dice. If u used dice with 2^64 faces u would get other results.

Um, okay.  Let's look at it with continuous probabilities on the range 0..1 then.

Wallet A has a 100K account and wallet B has a 50K account.  Wallet A throws am infinite-sided die mapped to 0..1 and gets N1, wallet B throws the same infinite-sided die and gets N2. 

Wallet A then takes a default generation time of (say) 10M seconds and divides by 100K x N1, while Wallet B takes the same default generation time and divides by 50K x N2. 

If B gets the shorter/first time, B forges the new block while if A gets the shorter/first time, A forges the new block.

So, for A:  10M seconds /(100K x N1) = 100 seconds / N1
while, for B:  10M seconds/(50K x N2) = 200 seconds / N2

And that means that if N1 < N2 (ie half the time) A always forges the block.

Otherwise, if N1 < N2/2, (ie, half the remaining time) A always forges the block.

Otherwise, N1 > N2/2, and B forges the block. 

I ignore the case where N1 == N2/2; we were throwing infnite-sided dice so the probability is infinitesimal.

[opticalcarrier]

The analogy with throwing dice is for illustrative purposes only.

This is the problem. 100K account does have advantage over 100x 1K accounts. But this advantage is small. In ur example it's noticeable coz u use conventional dice. If u used dice with 2^64 faces u would get other results.

Um, okay.  Let's look at it with continuous probabilities on the range 0..1 then.

Wallet A has a 100K account and wallet B has a 50K account.  Wallet A throws am infinite-sided die mapped to 0..1 and gets N1, wallet B throws the same infinite-sided die and gets N2. 

Wallet A then takes a default generation time of (say) 10M seconds and divides by 100K x N1, while Wallet B takes the same default generation time and divides by 50K x N2. 

If B gets the shorter/first time, B forges the new block while if A gets the shorter/first time, A forges the new block.

So, for A:  10M seconds /(100K x N1) = 100 seconds / N1
while, for B:  10M seconds/(50K x N2) = 200 seconds / N2

And that means that if N1 < N2 (ie half the time) A always forges the block.

Otherwise, if N1 < N2/2, (ie, half the remaining time) A always forges the block.

Otherwise, N1 > N2/2, and B forges the block. 

I ignore the case where N1 == N2/2; we were throwing infnite-sided dice so the probability is infinitesimal.

but doesnt that correspond with what we expect as normal, where 1 out of every 3 blocks is forged by B, and 2 out of every 3 blocks is forged by A; since A has 2x as much NXT as B, then it will forge 2x as many blocks?

[Cryddit]

So, for A:  10M seconds /(100K x N1) = 100 seconds / N1
while, for B:  10M seconds/(50K x N2) = 200 seconds / N2

And that means that if N1 < N2 (ie half the time) A always forges the block.

Otherwise, if N1 < N2/2, (ie, half the remaining time) A always forges the block.

Otherwise, N1 > N2/2, and B forges the block. 

but doesnt that correspond with what we expect as normal, where 1 out of every 3 blocks is forged by B, and 2 out of every 3 blocks is forged by A; since A has 2x as much NXT as B, then it will forge 2x as many blocks?

I think it corresponds with the case where A forges 3/4 of the blocks and B forges 1/4 of the blocks, which gives A more advantage than we expect or desire; with 2x as much balance, A ought to be forging 2/3 not 3/4.

I'm going to write a toy simulation and check this; it's possible that in my gedanken experiment I messed up some statistics and that in a simulation I won't.

[Cryddit]

confirmed.  A doubled balance appears to give triple the forging power rather than double.  Doesn't matter how many "sides" the dice have.

In my example I tried 100K trials and got splits of about 75K and 25K (plus-minus statistical noise).

Here is the very simple C code;

#include <stdlib.h>
#include <stdio.h>

// takes a balance; returns an interval to block forging time. 
double rollem(double balance){
  double roll = 0.0;
  while (roll == 0.0) 
     roll = ((double) rand())/RAND_MAX; // no divisions by zero
  return 1000 / (balance * roll);
}


// tries a hundred thousand trials and reports the advantage of an 
// account with supposedly 2x as much forging power.
main(){
  double A = 10000000;
  double B = 5000000;

  double Atime;
  double Btime;

  int count;
  int Acount = 0;
  int Bcount = 0;

  for (count = 0; count < 100000; count++){
    do{
      Atime = rollem (A);
      Btime = rollem (B);
    }while (Atime == Btime); // no ties count. 
    if (Atime < Btime) Acount++;
    else Bcount++;
  }
  printf("\nA forged %d blocks, B forged %d blocks\n", Acount, Bcount);
  printf("With A balance = 2x B balance, A forged %f times as many blocks.\n\n", 
    ((double)Acount) / Bcount);
}

And here's the compile/run:

~/src/Cred/testprogs$ gcc -o nxtforging nxtforging.c 
~/src/Cred/testprogs$ ./nxtforging

A forged 75141 blocks, B forged 24859 blocks
With A balance = 2x B balance, A forged 3.022688 times as many blocks.

~/src/Cred/testprogs$

[Come-from-Beyond]

Alice rolls 1000-face die. Bob rolls 1000-face die.
Alice wins if she gets 1 or 2 (her balance is 100k), Bob wins if he gets 1 (his balance is 50k).

How many times Alice will win if she rolls the die 1000 times?
How many times Bob will win if he rolls the die 1000 times?

Could anyone answer the questions above?

[jettico]

This code in python

import random

NBLOCKS = 1000000
W1 = 1000
W2 = 100000

na = nb = 0.

for x in xrange(NBLOCKS):
    a = random.uniform(0, 1./W1)
    b = random.uniform(0, 1./W2)

    if a<b:
        na += 1
    elif a>b:
        nb += 1

print nb/na

200.369311317

(instead of 100 as expected)

is the DIRECT and VERBATIM implementation of this algorithm:

Do http://localhost:7874/nxt?requestType=getState to get value of "lastBlock"
1) Do http://localhost:7874/nxt?requestType=getBlock&block=10621696942372068326 (assuming 10621696942372068326 is the value of "lastBlock")
2) Convert "generationSignature" into binary, and append the public key bytes returned by getAccountPublicKey
3) Calculate SHA256 (generationSignature, publicKey)
4) The first 8 bytes of this value, as an unsigned long in little-endian notation, is the "HIT" value
5) The value of "baseTarget", multiplied by the effective balance of the account, is STATIC_TARGET
6) Repeat steps 3-6 for each active account, and find the one with lowest HIT/STATIC_TARGET ratio. This account will forge the next block

taken from here: http://wiki.nxtcrypto.org/wiki/Transparent_Forging

Your game of dice has no connection to this algorithm.

[Come-from-Beyond]

Your game of dice has no connection to this algorithm.

What about the answers on my questions?

[jettico]

confirmed.  A doubled balance appears to give triple the forging power rather than double.  Doesn't matter how many "sides" the dice have.

In my example I tried 100K trials and got splits of about 75K and 25K (plus-minus statistical noise).

Here is the very simple C code; <...>

[/pre]

This code is good. Although it still has a small imperfection:

From those steps of the algorithm

3) Calculate SHA256 (generationSignature, publicKey)
4) The first 8 bytes of this value, as an unsigned long in little-endian notation, is the "HIT" value
6) Repeat steps 3-6 for each active account, and find the one with lowest HIT/STATIC_TARGET ratio

it is clear that it should be

 return 1000 *  roll / balance;

instead of

 return 1000 / (balance * roll);

But it doesn't affect the result because the distribution is uniform.

So yes, I confirm that:
  1) this program produces the provided result (I reproduced it by compiling and running on my computer)
  2) with the above-mentioned fix it correctly models the algorithm described in the wiki (and produces the same result as without the correction).

[jettico]

Your game of dice has no connection to this algorithm.

What about the answers on my questions?

Those questions are unrelated to the Transparent Forging.

Start a new forum thread, let's discuss this new problem there, or explain how it relates to Transparent Forging.

[Come-from-Beyond]

Your game of dice has no connection to this algorithm.

What about the answers on my questions?

Those questions are unrelated to the Transparent Forging.

Start a new forum thread, let's discuss this new problem there, or explain how it relates to Transparent Forging.

Well, it is related to TF. Ur model is not.

U can answer my questions and we continue the discussion.

[jettico]

I can instead create a FAQ about my code.

Q: Why do you use random() instead of first 8 bytes of SHA256 of the transaction hash as described in the algorithm?
A: Because SHA256 is designed to generate values that are uniformly distributed.

Q: What happens if a==b? Why don't you process this situation?
A: The original algorithm described in wiki doesn't give the answer either. But the possibility of this event is proportional to (2^-64)² (because 8 first bytes of sha256 have 64 bits) which is about 10^-38 so it is safe in this code to simple skip such cases for clarity. If you are feeling pedantic you can add the line

print NBLOCKS-(na+nb)

in the end of the code and it will always (well, ok, with an estimated probability of 1-NBLOCKS*(10^-38) = 1-10^-32) give you zero.

[Come-from-Beyond]

I can instead create a FAQ about my code.

Q: Why do you use random() instead of first 8 bytes of SHA256 of the transaction hash as described in the algorithm?
A: Because SHA256 is designed to generate values that are uniformly distributed.

Q: What happens if a==b? Why don't you process this situation?
A: The original algorithm described in wiki doesn't give the answer either. But the possibility of this event is proportional to (2^-64)² (because 8 first bytes of sha256 have 64 bits) which is about 10^-38 so it is safe in this code to simple skip such cases for clarity. If you are feeling pedantic you can add the line

print NBLOCKS-(na+nb)

in the end of the code and it will always (well, ok, with an estimated probability of 1-NBLOCKS*(10^-38) = 1-10^-32) give you zero.

Hehe, why r u affraid of answering my questions?

[jettico]

The analogy with throwing dice is for illustrative purposes only.

This is the problem. 100K account does have advantage over 100x 1K accounts. But this advantage is small. In ur example it's noticeable coz u use conventional dice. If u used dice with 2^64 faces u would get other results.

100K account is 10000 times more likely to forge a block than any single account of 1K, and 100 times more than all of them combined.

I tell you once again. I mention dice to illustrate WHY the algorithm is wrong, run my code Cryddit's code or if you want to make sure IF the algorithm is wrong.

Well, it is related to TF. Ur model is not.

Proof?

[Come-from-Beyond]

Well, it is related to TF. Ur model is not.

Proof?

We'll come to it step by step. The 1st step requires u to answer the questions.

[jettico]

I can instead create a FAQ about my code.

Q: Why do you use random() instead of first 8 bytes of SHA256 of the transaction hash as described in the algorithm?
A: Because SHA256 is designed to generate values that are uniformly distributed.

Q: What happens if a==b? Why don't you process this situation?
A: The original algorithm described in wiki doesn't give the answer either. But the possibility of this event is proportional to (2^-64)² (because 8 first bytes of sha256 have 64 bits) which is about 10^-38 so it is safe in this code to simple skip such cases for clarity. If you are feeling pedantic you can add the line

print NBLOCKS-(na+nb)

in the end of the code and it will always (well, ok, with an estimated probability of 1-NBLOCKS*(10^-38) = 1-10^-32) give you zero.

Hehe, why r u affraid of answering my questions?

No, I'm ignoring your attempt to substitute notions (we both remember that you've done it before, and last time you failed to explain how the substituted notion related to my original post).

Start a new thread and I shall answer it there.

I'm not willing to continue this senseless flood any longer. It doesn't help anyone. If you don't believe me or Cryddit ask someone whom you believe. Ask BCNext, ask Jean-Luc.

[Come-from-Beyond]

No, I'm ignoring your attempt to substitute notions (we both remember that you've done it before).

Start a new thread and I shall answer it there.

Ok. Keep ignoring. Discussion is over, we'll continue it after I get the answers.

[jettico]

We'll come to it step by step. The 1st step requires u to answer the questions.

btw, this is childish. I'm ready to answer any of your questions related to my original post. This question is not until you explain how.

[starik69]

Jettico, you are wrong. 

[Come-from-Beyond]

We'll come to it step by step. The 1st step requires u to answer the questions.

btw, this is childish. I'm ready to answer any of your questions related to my original post. This question is not until you explain how.

I don't blame u, coz there is no a good explanation how forging works, but I'm quite tired to explain why people r wrong with their models. In ur case u r wrong coz u analyze an impossible situation when there r only 2 forging accounts in the system. Models doesn't work in extremum conditions.

[BloodyRookie]

Alice rolls 1000-face die. Bob rolls 1000-face die.
Alice wins if she gets 1 or 2 (her balance is 100k), Bob wins if he gets 1 (his balance is 50k).

How many times Alice will win if she rolls the die 1000 times?
How many times Bob will win if he rolls the die 1000 times?

Could anyone answer the questions above?

Your premise means that if Alice gets 1 and Bob gets 1, both win. Is that really what you want it to be?

[BloodyRookie]

We'll come to it step by step. The 1st step requires u to answer the questions.

btw, this is childish. I'm ready to answer any of your questions related to my original post. This question is not until you explain how.

I don't blame u, coz there is no a good explanation how forging works, but I'm quite tired to explain why people r wrong with their models. In ur case u r wrong coz u analyze an impossible situation when there r only 2 forging accounts in the system. Models doesn't work in extremum conditions.

So you agree that in the case of only 2 forgers, their analysis is ok?

[Come-from-Beyond]

So you agree that in the case of only 2 forgers, their analysis is ok?

No.

[Come-from-Beyond]

Your premise means that if Alice gets 1 and Bob gets 1, both win. Is that really what you want it to be?

Yes, if both get 1 then both win but one of the blocks will be orphaned.

[martismartis]

Your premise means that if Alice gets 1 and Bob gets 1, both win. Is that really what you want it to be?

Yes, if both get 1 then both win but one of the blocks will be orphaned.

Which one and why?

[Come-from-Beyond]

Your premise means that if Alice gets 1 and Bob gets 1, both win. Is that really what you want it to be?

Yes, if both get 1 then both win but one of the blocks will be orphaned.

Which one and why?

Depends on network topology. Blockchain can't have more than 1 block at a particular height.

[jettico]

I don't blame u, coz there is no a good explanation how forging works, but I'm quite tired to explain why people r wrong with their models. In ur case u r wrong coz u analyze an impossible situation when there r only 2 forging accounts in the system. Models doesn't work in extremum conditions.

At leeeast a sensible argument!

Let's see!

Code:

from random import random
from operator import itemgetter

NBLOCKS = 100000
N = 100
W = [100000] + [1000] * N
z = [0.] * len(W)
wins = [0] * len(W)

for x in xrange(NBLOCKS):
	for i in xrange(len(W)):
		z[i] = random()/W[i]
	
	[position, value] = min(enumerate(z), key=itemgetter(1))
	wins[position] += 1

print float(wins[0])/sum(wins[1:]), float(wins[0])/(sum(wins[1:])/N)

1.72101439417 172.340599455

(instead of 1 and 100)

Not THAT bad, but still!

[Come-from-Beyond]

Not THAT bad, but still!

Still far from the reality.

[ejhuff]

Alice rolls 1000-face die. Bob rolls 1000-face die.
Alice wins if she gets 1 or 2 (her balance is 100k), Bob wins if he gets 1 (his balance is 50k).

How many times Alice will win if she rolls the die 1000 times?
How many times Bob will win if he rolls the die 1000 times?

Could anyone answer the questions above?

Here are some simulation results:

Code:

    seed = 0x000004d2 =     1234
RAND_MAX = 0x7fffffff = 2147483647
   RETRY = 0x7ffffd78 = 2147483000
In 1000000 total trials of 1000 throws each, Alice won (2 chances in 1000 per throw) as follows:
Alice won 0 times in 135332 of the trials.
Alice won 1 times in 270858 of the trials.
Alice won 2 times in 271239 of the trials.
Alice won 3 times in 180359 of the trials.
Alice won 4 times in 90048 of the trials.
Alice won 5 times in 35744 of the trials.
Alice won 6 times in 11955 of the trials.
Alice won 7 times in 3388 of the trials.
Alice won 8 times in 858 of the trials.
Alice won 9 times in 179 of the trials.
Alice won 10 times in 35 of the trials.
Alice won 11 times in 4 of the trials.
Alice won 12 times in 1 of the trials.
In 1000000 total trials of 1000 throws each, Bob won (1 chance in 1000 per throw) as follows:
Bob won 0 times in 368738 of the trials.
Bob won 1 times in 368080 of the trials.
Bob won 2 times in 183462 of the trials.
Bob won 3 times in 60983 of the trials.
Bob won 4 times in 15109 of the trials.
Bob won 5 times in 3063 of the trials.
Bob won 6 times in 484 of the trials.
Bob won 7 times in 76 of the trials.
Bob won 8 times in 5 of the trials.
In 1000000 total trials of 1000 throws each, They both won (2 chances in 1000000 per throw) as follows:
Both won 0 times in 998026 of the trials.
Both won 1 times in 1973 of the trials.
Both won 2 times in 1 of the trials.
Number of random numbers drawn = 0x0077359654
              estimated period = 0x07fffffff0

Another try with different random numbers

Code:

    seed = 0x00003039 =    12345
RAND_MAX = 0x7fffffff = 2147483647
   RETRY = 0x7ffffd78 = 2147483000
In 1000000 total trials of 1000 throws each, Alice won (2 chances in 1000 per throw) as follows:
Alice won 0 times in 135982 of the trials.
Alice won 1 times in 270421 of the trials.
Alice won 2 times in 270428 of the trials.
Alice won 3 times in 180820 of the trials.
Alice won 4 times in 90182 of the trials.
Alice won 5 times in 35843 of the trials.
Alice won 6 times in 11828 of the trials.
Alice won 7 times in 3425 of the trials.
Alice won 8 times in 839 of the trials.
Alice won 9 times in 195 of the trials.
Alice won 10 times in 32 of the trials.
Alice won 11 times in 4 of the trials.
Alice won 12 times in 1 of the trials.
In 1000000 total trials of 1000 throws each, Bob won (1 chances in 1000 per throw) as follows:
Bob won 0 times in 368609 of the trials.
Bob won 1 times in 368350 of the trials.
Bob won 2 times in 183326 of the trials.
Bob won 3 times in 61018 of the trials.
Bob won 4 times in 15096 of the trials.
Bob won 5 times in 3052 of the trials.
Bob won 6 times in 467 of the trials.
Bob won 7 times in 71 of the trials.
Bob won 8 times in 11 of the trials.
In 1000000 total trials of 1000 throws each, They both won (2 chances in 1000000 per throw) as follows:
Both won 0 times in 998103 of the trials.
Both won 1 times in 1892 of the trials.
Both won 2 times in 5 of the trials.
Number of random numbers drawn = 0x007735962c
              estimated period = 0x07fffffff0

Both win when Bob rolls 1 and Alice rolls 1 or 2, which is twice in the 1000000 possible rolls of two 1000 face dice.
Throwing 2 dice 1000 times each (1 trial), we should never see both win.
Throwing 2 dice 1000 x 1000000 times (1000000 trials), we should see both win about 2000 times, which we do.

[aljazstraser]

I am new with NXT.. can someone explain me in few words, why i should start dealing with "next generation coins". I saw videos, but still i need to hear it from more experienced users.

Thanks in advance

[liyi3c]

Now imagine that you throw a dice with numbers from 1 to 6 and your opponent throws a semi-dice with three possible values from 1 to 3.

this analogy doesn't match forging properly, as the second dice(1-3) can't be treated uniform distribution. Instead, the p(1) = 1/6, p(2) = 1/6, p(3) = 2/3 which should also includes the implicitly removed p(4),p(5),p(6) in your analogy.
in this way, the ratio should be 2 rather than 3.

edit: if 100k divided into 100*1k, 100*p(1k gen Block) will be slightly lower than p(100k gen Block) as generation mutual exclusion

[jettico]

Still far from the reality.

The reality is that your algorithm is wrong.

[Cryddit]

Ok. Keep ignoring. Discussion is over, we'll continue it after I get the answers.

Dude, there is no way someone capable of writing code is also capable of the kind of category error that would make them think there are relevant questions to ask. 

The entire purpose of code is to specify a process so exactly that there is no room for questions.  And you're looking at a thread in which two different people have posted code.  There is no possible question about what the code means that the code itself does not completely and unambiguously answer. 

The algorithm you described either is, or is not, accurately implemented by the code presented.  There are no questions to ask here.  You understand the algorithm because it's your algorithm in the first place.  If the code doesn't implement it correctly, then it's because there is an error in the code or because the description you gave isn't correct, and only you can explain the error or provide the correction.  There are no questions you can ask someone else to address that, because that knowledge is yours alone.  It does not belong to anyone else whom you could ask a question.  If the code does match, then the effect it demonstrates is an effect of the algorithm.  And if that's true, then only you as the developer can decide whether to do anything about it and if so what.  Again, no questions you can ask anyone else are relevant, because it's your decision not anyone else's.   

So I only have one question; why are you pretending to have a problem understanding this?

[Come-from-Beyond]

Still far from the reality.

The reality is that your algorithm is wrong.

I disagree.

[starik69]

There are no questions to ask here.

Even if those two don't understand math?

[Come-from-Beyond]

And you're looking at a thread in which two different people have posted code.

Both the people made the same error.

So I only have one question; why are you pretending to have a problem understanding this?

Already answered why ur model is incorrect. Sorry, I'm not going to waste my time on every guy who does a logical error.

[Come-from-Beyond]

@ All:

If u r going to bother me with the same issue again and again, please, make sure that blockchain data proves ur math. Till now the data proves that I'm right.

[Cryddit]

For what it's worth, come-from-beyond has a point when he says that the situation is exaggerated by an artificial situation with just two accounts.  

I decided to try a broader simulation, and see what the effects are.  

So, I set this up with 26 accounts, each having a different balance from 1000 to 26000, and bumped it up to a million trials to get consistent results despite statistical noise having a greater impact on a more complex situation.

Here's the code:

Code:

#include <stdlib.h>
#include <stdio.h>

// takes a balance; returns an interval to block forging time. 
double rollem(double balance){
  double roll = 0.0;
  while (roll == 0.0) roll = ((double) rand())/RAND_MAX;
  return 1000 * roll / balance;
}


main(){
  double balances[26], times[26];
  double min, totalmoney = 0.0;
  int wins[26];
  int winner, count, trial, TRIALS = 1000000;

  for (count = 0; count < 26; count++){
    balances[count] = (count+1) * 1000;
    totalmoney += balances[count];
    wins[count] = 0;
  }

  for (trial = 0; trial < TRIALS; trial++){
    for (count = 0; count < 26; count++){
      times[count] = rollem(balances[count]);
    }
    min = times[0];
    winner = 0;
    for (count = 1; count < 26; count++)
      if (min > times[count]){
	min = times[count];
	winner = count;
      }
    wins[winner]++;
  }
  for (count = 0; count < 26; count++){
    printf("%c got %f%% of the wins with %f%% of the money.\n", count+'A', 
	   100*(double)wins[count]/TRIALS, 
	   100*(double)balances[count]/totalmoney);
  }
}

The effect is still present, in that the accounts with larger than median balances get more than their share of blocks, but it's considerably less important given the number of accounts and range of account values under consideration.  I deliberately let the smaller account win the block in every tie, just to ensure that the bias demonstrated was not due to a systematic error going the other direction. 

In this broader simulation, people do not get three times the number of blocks relative to someone with half their balance; Instead they get only a tiny fraction more than double.  (note, these pairs are AB, BD, CF, DH, EJ, and so on).

Here are the results:  


A got 0.269800% of the wins with 0.284900% of the money.
B got 0.545100% of the wins with 0.569801% of the money.
C got 0.832000% of the wins with 0.854701% of the money.
D got 1.076900% of the wins with 1.139601% of the money.
E got 1.364900% of the wins with 1.424501% of the money.
F got 1.627700% of the wins with 1.709402% of the money.
G got 1.925300% of the wins with 1.994302% of the money.
H got 2.226500% of the wins with 2.279202% of the money.
I got 2.473800% of the wins with 2.564103% of the money.
J got 2.812900% of the wins with 2.849003% of the money.
K got 3.108000% of the wins with 3.133903% of the money.
L got 3.333500% of the wins with 3.418803% of the money.
M got 3.667000% of the wins with 3.703704% of the money.
N got 3.954400% of the wins with 3.988604% of the money.
O got 4.229700% of the wins with 4.273504% of the money.
P got 4.554900% of the wins with 4.558405% of the money.
Q got 4.813100% of the wins with 4.843305% of the money.
R got 5.146400% of the wins with 5.128205% of the money.
S got 5.400300% of the wins with 5.413105% of the money.
T got 5.720200% of the wins with 5.698006% of the money.
U got 6.039900% of the wins with 5.982906% of the money.
V got 6.336200% of the wins with 6.267806% of the money.
W got 6.610200% of the wins with 6.552707% of the money.
X got 7.018400% of the wins with 6.837607% of the money.
Y got 7.296000% of the wins with 7.122507% of the money.
Z got 7.616900% of the wins with 7.407407% of the money.

[opticalcarrier]

For what it's worth, come-from-beyond has a point when he says that the situation is exaggerated by an artificial situation with just two accounts. 

I decided to try a broader simulation, and see what the effects are. 

So, I set this up with 26 accounts, each having a different balance from 1000 to 26000, and bumped it up to a million trials to get consistent results despite statistical noise having a greater impact on a more complex situation.

Here's the code:

Code:

#include <stdlib.h>
#include <stdio.h>

// takes a balance; returns an interval to block forging time. 
double rollem(double balance){
  double roll = 0.0;
  while (roll == 0.0) roll = ((double) rand())/RAND_MAX;
  return 1000 * roll / balance;
}


main(){
  double balances[26], times[26];
  double min, totalmoney = 0.0;
  int wins[26];
  int winner, count, trial, TRIALS = 1000000;

  for (count = 0; count < 26; count++){
    balances[count] = (count+1) * 1000;
    totalmoney += balances[count];
    wins[count] = 0;
  }

  for (trial = 0; trial < TRIALS; trial++){
    for (count = 0; count < 26; count++){
      times[count] = rollem(balances[count]);
    }
    min = times[0];
    winner = 0;
    for (count = 1; count < 26; count++)
      if (min > times[count]){
	min = times[count];
	winner = count;
      }
    wins[winner]++;
  }
  for (count = 0; count < 26; count++){
    printf("%c got %f%% of the wins with %f%% of the money.\n", count+'A', 
	   100*(double)wins[count]/TRIALS, 
	   100*(double)balances[count]/totalmoney);
  }
}

The effect is still present, in that the accounts with larger than median balances get more than their share of blocks, but it's considerably less important given the number of accounts and range of account values under consideration. 

In particular, people do not get three times the number of blocks relative to someone with half their balance; Instead they get only a tiny fraction more than double.  (note, these pairs are AB, BD, CF, DH, EJ, and so on).

Here are the results: 


A got 0.269800% of the wins with 0.284900% of the money.
B got 0.545100% of the wins with 0.569801% of the money.
C got 0.832000% of the wins with 0.854701% of the money.
D got 1.076900% of the wins with 1.139601% of the money.
E got 1.364900% of the wins with 1.424501% of the money.
F got 1.627700% of the wins with 1.709402% of the money.
G got 1.925300% of the wins with 1.994302% of the money.
H got 2.226500% of the wins with 2.279202% of the money.
I got 2.473800% of the wins with 2.564103% of the money.
J got 2.812900% of the wins with 2.849003% of the money.
K got 3.108000% of the wins with 3.133903% of the money.
L got 3.333500% of the wins with 3.418803% of the money.
M got 3.667000% of the wins with 3.703704% of the money.
N got 3.954400% of the wins with 3.988604% of the money.
O got 4.229700% of the wins with 4.273504% of the money.
P got 4.554900% of the wins with 4.558405% of the money.
Q got 4.813100% of the wins with 4.843305% of the money.
R got 5.146400% of the wins with 5.128205% of the money.
S got 5.400300% of the wins with 5.413105% of the money.
T got 5.720200% of the wins with 5.698006% of the money.
U got 6.039900% of the wins with 5.982906% of the money.
V got 6.336200% of the wins with 6.267806% of the money.
W got 6.610200% of the wins with 6.552707% of the money.
X got 7.018400% of the wins with 6.837607% of the money.
Y got 7.296000% of the wins with 7.122507% of the money.
Z got 7.616900% of the wins with 7.407407% of the money.

very cool simulation.  that started leveling out very quickly from just 2 accounts to 26.

[Cryddit]

And you're looking at a thread in which two different people have posted code.

Both the people made the same error.

And you have not yet said what that error is.  In fact you flatly refused to on several occasions.  The supposed error does not in fact exist. 

You were right when you said that the artificial situation of just two accounts exaggerated the effect; That doesn't mean there was an error -- the bias unquestionably exists. 

So I only have one question; why are you pretending to have a problem understanding this?

Already answered why ur model is incorrect. Sorry, I'm not going to waste my time on every guy who does a logical error.

Nope, sorry.  Remember, You flatly refused to explain. You don't get to flatly refuse to explain, and then claim that you did. 

The model is correct; The only question is, does it matter?   And the answer given the broader simulation above is, probably not. With many accounts no one having more than a small fraction of the total money, the bias is very small.  But it definitely does exist.

[Come-from-Beyond]

And you have not yet said what that error is.  In fact you flatly refused to on several occasions.  The supposed error does not in fact exist. 

You were right when you said that the artificial situation of just two accounts exaggerated the effect; That doesn't mean there was an error -- the bias unquestionably exists. 

Nope, sorry.  Remember, You flatly refused to explain. You don't get to flatly refuse to explain, and then claim that you did. 

The model is correct; The only question is, does it matter?   And the answer given the broader simulation above is, probably not. With many accounts no one having more than a small fraction of the total money, the bias is very small.  But it definitely does exist.

The error I'm talking about is an attempt to model forging with 2 accounts only.

Bias does exist, I was always saying this when discussed with other guys who asked the same questions. But it's very small to pay attention, close to dispersion (subject to account balances). I refused to explain coz practice proves my position and it's YOU who is supposed to prove that ur model is correct.

[etlase3]

I refused to explain coz practice proves my position and it's YOU who is supposed to prove that ur model is correct.

So if practice proves your position, and I flip heads 10 times in a row, that means I will never flip tails? Practice proves that the coin always lands on heads.

[Come-from-Beyond]

I refused to explain coz practice proves my position and it's YOU who is supposed to prove that ur model is correct.

So if practice proves your position, and I flip heads 10 times in a row, that means I will never flip tails? Practice proves that the coin always lands on heads.

It's the 2nd time u post nonsense in an Nxt thread.

[etlase3]

I think your nonsense indicator is badly broken.

[Come-from-Beyond]

I think your nonsense indicator is badly broken.

Thank u for ur competent opinion.

[klee]

I think your nonsense indicator is badly broken.

Thank u for ur competent opinion.

It is the n-th time you say this - I will put you on my ignore list for 6.8 days!
 

[ZeroTheGreat]

So if practice proves your position, and I flip heads 10 times in a row, that means I will never flip tails? Practice proves that the coin always lands on heads.

If there's a model that predicts HUGE difference, there'd be some numbers for that in statisticks, don't u think? For now it seems, difference not exist at all (we've not too much data and topology non-optimized), but if we'll follow the logic (there're 100s of 2^N-dices and only 1 winner), difference'd be incredible small at longer distance. I'm comfortable with that.

[Cryddit]

Come-from-Beyond, I don't know how to interact with you. 

When demonstrating a bias, the first thing to do is always to identify the case where returns deviate very sharply from expectations.  That was the case you pooh-poohed. 

Then I went on to demonstrate that even in much larger simulations the bias, though its effects are reduced, is still present.  That you took as an admission that I was wrong.

You flatly refused to explain yourself, then later refused again with the claim that you had explained yourself and don't care to do it again.

You're also responding to technical truths as personal attacks, and trying to deal with facts as though they were merely social conventions, with bluff and aggressiveness and fabrications rather than other facts.

It seems to me as if your brain is somehow broken, and I don't know where the edges of rationality that I can converse with might be.  Interacting with you makes me angry and I tend to snap at you; I'm sorry for that, but I can't otherwise seem to communicate with you at all.   

[Come-from-Beyond]

Then I went on to demonstrate that even in much larger simulations the bias, though its effects are reduced, is still present.  That you took as an admission that I was wrong.

No, I said that u r wrong when used a model with 2 accounts only. U r right, there is a bias. And I stated this a lot of times.

[opticalcarrier]

ok, in order to meet 1Mtps, wont blocks be forged much more frequently than 1 per minute?  Is this necessarily a "bad" situation, or just out of the "normal" figure of 1 block per minute?

And what exactly does it mean to "send transactions directly to the next-scheduled forger"?  How is this accomplished? Are these forgers going to have to act as some kind of service provider where their public IPs are known?

[Come-from-Beyond]

ok, in order to meet 1Mtps, wont blocks be forged much more frequently than 1 per minute?  Is this necessarily a "bad" situation, or just out of the "normal" figure of 1 block per minute?

And what exactly does it mean to "send transactions directly to the next-scheduled forger"?  How is this accomplished? Are these forgers going to have to act as some kind of service provider where their public IPs are known?

Gap between blocks will be exactly 1 minute.

Yes, these forgers have to announce IP address for transactions.

[ChuckOne]

If they miss their chance to mine a block they'll be penalized. Stakeholders r supposed to protect Nxt, not just sit and wait for 1 NXT = 1,000,000 USD day.

NB: The only penalty is inability to mine blocks within some period of time. They still can decide not to bother with mining, but their "hashing" power will be distributed to those who do protect the network.

When will this penalty be implemented?

No ETA yet.

Any news on that one?

[jl777]

It seems one of BCNext plans tackles this stuff?

Yes, but he is upset that community doesn't wish to review and develop his ideas. Anon136 is the only one who does.

I think the majority of people here are interested in reviewing and developing his (BCNext) ideas, we just need a little structured guidance, this thread is so massive.

yup. same here. I am barely hanging on with hanging on.

I guess we should head over to https://bitcointalk.org/index.php?topic=364218.0 and discuss our TF ideas.

(Re)starting discussion on reviewing and developing TF

If BCNext likes what you are doing, you will get added to NXT credits API!

James

[Come-from-Beyond]

If BCNext likes what you are doing, you will get added to NXT credits API!

BCNext likes every attempt to review his ideas.

[ChuckOne]

Alice rolls 1000-face die. Bob rolls 1000-face die.
Alice wins if she gets 1 or 2 (her balance is 100k), Bob wins if he gets 1 (his balance is 50k).

How many times Alice will win if she rolls the die 1000 times?
How many times Bob will win if he rolls the die 1000 times?

Could anyone answer the questions above?

Let me think about this.

One roll of a die is a Bernoulli trail, so we should have two binomial distributions B(1000, 0.002) and B(1000, 0.001).

The expected value should be 2 and 1 respectively if I am not completely mistaken.

[Come-from-Beyond]

Let me think about this.

One roll of a die is a Bernoulli trail, so we should have two binomial distributions B(1000, 0.002) and B(1000, 0.001).

The expected value should be 2 and 1 respectively if I am not completely mistaken.

I think u r right.

[jl777]

If BCNext likes what you are doing, you will get added to NXT credits API!

BCNext likes every attempt to review his ideas.

If he likes "attempt" then I have attempted a LOT! Just havent felt like I truly understand it well enough to be able to analyze it, let alone develop new ideas.

My hope is that I will be able to present specific functionality that can only be properly implemented using TF. Even if I cant understand TF fully, I hope that it will spur others who do to figure out how to properly implement the new functionality.

James

[ChuckOne]

Let me think about this.

One roll of a die is a Bernoulli trail, so we should have two binomial distributions B(1000, 0.002) and B(1000, 0.001).

The expected value should be 2 and 1 respectively if I am not completely mistaken.

I think u r right.

So, how do we continue? You said we make it step by step.

[Come-from-Beyond]

So, how do we continue? You said we make it step by step.

Cryddit already showed that forging is ok - https://bitcointalk.org/index.php?topic=364218.msg4861016#msg4861016

[ChuckOne]

So, how do we continue? You said we make it step by step.

Cryddit already showed that forging is ok - https://bitcointalk.org/index.php?topic=364218.msg4861016#msg4861016

Err, so this thread can be closed?

EDIT: a simulation suffices?

[Come-from-Beyond]

So, how do we continue? You said we make it step by step.

Cryddit already showed that forging is ok - https://bitcointalk.org/index.php?topic=364218.msg4861016#msg4861016

Err, so this thread can be closed?

EDIT: a simulation suffices?

This thread is about another thing. One guy just derailed it.

Simulation is enough, at least for me.

[jl777]

If BCNext likes what you are doing, you will get added to NXT credits API!

BCNext likes every attempt to review his ideas.

I will present a proposal on NXT core change that will give NXT fundamentally more value and allow it to become platform for all types of new functionality. Like Internet protocol did.

First, I want to make sure I at least understand the current expected implementation of NXT VM (Turing scripts) as to what it is able to do. My understanding is that it will be able to access the "entire state of NXT blockchain", so aliases, AM, etc. anything that is in the blockchain, it can access. With the concept of externally pushing down into an AM any additional data needed, the input side for the NXT VM seems well covered.

It is the output side that I am concerned with. I believe as it stands now, it will be able to send NXT and save an AM. My proposal is based on this limitation. If this is all that NXT VM can do, it means that ANY OTHER side effect of NXT VM cannot be trustless nor decentralized.

For clarity, let's say "side effect" is to send and email. I choose this example as I assume it is possible to send an email using Java with little effort and jean-luc won't yell at me about making him do horrible things to the code. The NXT core email SMTP side effect, can generate a hash on the contents and recipient of the email and use that for TXID to be put into NXT email blockchain (or even main blockchain). The importance of something being in the blockchain is that it can be validated by all on the network. The importance of being implemented in the NXT core is that it is the only way for it to be able to be trusted.

So, using the above mechanism, any side effect that can be implemented into the NXT core can implement a decentralized and trustless solution that is controlled by the NXT VM script. However, one problem that I see is that there is no assurance that the NXT VM's output AM is going to be parsed properly and the NXT smtp invoked.

Without a way to assure a once and only once invocation of "side effect" that we can rely on being used, the power of NXT VM is limited to the self-enclosed NXT universe. On the other hand, if we can ensure that "side effects" that are supported by NXT core do in fact get executed, it opens up vast new possibilities. VAST!

I want to take it one step further by having a NXT-plugin architecture defined. There are just some things that even I wouldn't want shoved into the NXT core, let alone jean-luc! So, we need a way to ensure that such external plugins are executed once and only once (similar to double spend problem). I imagine that not all NXT nodes will have support for all external plugins, but as long as the NXT hubs (> 100 servers) can run these external plugins, then I believe it will work.

So, finally here is my attempt at utilizing TF for this as so far it has been pretty mechanical. Assuming that the vast majority of forging is done by NXT nodes with a full set of external plugins, then within a reasonable number of blocks, the plugin will get invoked. We can use TF to see how many blocks we need to wait for the first forged block that is on a node capable of executing the external plugin! This is SUPER useful, since otherwise we would need to try to invoke the plugin, wait for error and then retry. MUCH better if we minimized errors in the first place.

I hope this is close to what BCNext is looking for?

Generalizing, for any plugin functionality there needs to be a way to invoke it once and only once and a way to verify it on all other nodes. For hardcoded plugins, we avoid the whole verification process. If there is a way for the NXTcore to get a read only pointer to the memory space of the plugin code space, the NXT core can add a function to verify the hash of the code space to verify that it is still running an unmodified version since the published source code of that plugin. So, maybe we just need to memory map the plugin and find its code, hopefully not too hard to do. Verification that the plugin has not been modified goes a long way to preventing Evil Bob from changing the code that implements the plugin. If the plugin code cannot be changed and it is correlated to published source code, then maybe even skeptics can trust that the NXT plugins will always do what they are supposed to. [I avoid discussion of proper error handling within the plugin as that is specific to each plugin]

So, at the very least the hardcoded plugin will allow NXT VM to affect the world outside the NXT blockchain and this is the key to being able to implement DAC. If we can make NXT plugins secure and verifiable, then NXT will be the first platform that allows anybody to create new functionality that is decentralized and can operate without trust by simply defining a "side effect" and a way to verify the side effect was actually done. Combine this with Transparent Forging's ability to predict the future forging nodes, allows a subset of NXT infrastructure to perform the plugins work.

Needless to say, achieving the above will make NXT like the Internet was when the only thing you could do was email. Order of magnitude increase in the utility is probably a gross underestimate.

James
 

[ChuckOne]

So, finally here is my attempt at utilizing TF for this as so far it has been pretty mechanical. Assuming that the vast majority of forging is done by NXT nodes with a full set of external plugins, then within a reasonable number of blocks, the plugin will get invoked. We can use TF to see how many blocks we need to wait for the first forged block that is on a node capable of executing the external plugin! This is SUPER useful, since otherwise we would need to try to invoke the plugin, wait for error and then retry. MUCH better if we minimized errors in the first place.

Don't know what you mean by: 'we invoke the plugin'. The node that is capable of executing the plugin executes it.
The execution of a script has to be done multiple times in order to verify its output.

[jl777]

So, finally here is my attempt at utilizing TF for this as so far it has been pretty mechanical. Assuming that the vast majority of forging is done by NXT nodes with a full set of external plugins, then within a reasonable number of blocks, the plugin will get invoked. We can use TF to see how many blocks we need to wait for the first forged block that is on a node capable of executing the external plugin! This is SUPER useful, since otherwise we would need to try to invoke the plugin, wait for error and then retry. MUCH better if we minimized errors in the first place.

Don't know what you mean by: 'we invoke the plugin'. The node that is capable of executing the plugin executes it.
The execution of a script has to be done multiple times in order to verify its output.

The script is validated by all the nodes, but the forging node needs to "send the email". We don't want to have multiple copies of the same email, even though it is not fatal. However, some plugins will have functionality that you wouldnt want to do more than once. TF allows all the nodes on the network to know which node will actually invoke the plugin and hence when they should be looking for PoP (proof of plugin) in the blockchain. By having the plugin run in a trusted framework, eg. NXTcore, proof of plugin could be as simple as verifying hash for the content of the email.

Sorry for mixing metaphors a bit in the above. It helps me to think in terms of a specific function when thinking about abstractions. Also, I am sure there are some (many?) technical issues with my proposal as it is.

My hope is that my initial proposal is close enough to the actual solution that allows us to find the perfect solution.

James

[ChuckOne]

My analysis so far:

Below u'll find a short description of Nxt mining system. The description is based on text written by BCNext, I paraphrase it in my own words to protect BCNext's real identity against text style analysis (as was agreed).

I want u to pay attention to a paper titled Decentralised Currencies Are Probably Impossible But Let’s At Least Make Them Efficient.

The author writes:

To match this to the notion of “decentralised” (i.e. lacking central authority), the consensus group must be, at least, all participants in the currency. This does not present any real problem when that group is known. For example, it would be possible to define the group as “all people currently in the United States”– where the currency would be something akin to the US Dollar. Assuming the majority decide to behave honestly (as seems likely, after all, that is what happens now), then they should have no difficulty in forming consensus on who has how much money at what time. However, the most general notion of decentralisation does not admit such re-strictions. After all, in some sense, placing any such restriction simply pushes the central authority back a layer: instead of controlling the currency, the authority controls membership of the consensus group. A system like this must allow any entity to participate, and to join and leave the scheme at will. And here lies the problem. If you can never know who is in the scheme (bear in mind that knowing who is in is also a consensus problem!), then you can never get agreement.

In Nxt this problem doesn't arise coz all participants (miners) r known.

I agree.

This is a side-effect of 100% proof-of-stake currency. [...]

It is like 'PPC in its completed form'. Its contributors are going to eventually dismiss PoW. Right now it's a hybrid system with declining PoW part. In the end, it will become 100% PoS as well. PoS is like recycling the already-mined resources and by doing so, receiving a bounty for recycling and therefore maintaining the resource flow.

As u may know, Bitcoin et al. can be attacked by an entity that possesses 51% of hashing power. 2 main scenarios r possible:
1. Part of the miners leave the "legit" branch of the blockchain and start mining their own branch.
2. Someone buys/produces mining equipment and starts mining secret branch.

It even leads to centralization as the ghash.io case showed. NXT could have a lower centralization because of it energy-efficient nature.
HOWEVER, have a look at http://www.nxtio.org/. Unfortunately, at first, people will resist; they don't want to give away their money. But in the end, they will contribute therefore increasing the accounts of nxtio.org further and further.

I as much as I value TF, I think one issue of it is driving many small shareholders into such pools aka centralization.

The 2nd scenario can't be applied to Nxt, coz no NXTs exist outside the network. [...]

To speak in the words of the author of the paper above, buying/producing mining equipment is therefore equivalent to buying NXTs: it is acquiring consensus power.
In case of NXT, the maximum consensus power is known in advance. That power can be distributed but in total it will never change.

[...]
BCNext is satisfied with the results shown during last 2 weeks and now is going to adjust the mining algo a little bit to make it transparent.

What does this transparency mean? It means that anyone can predict (with very high probability) who and when will generate next block(s). And this gives us superior advantages:
1. Transactions can be sent directly to the miner who will mine the next block (if he decides to reveal his location on the Internet), thus saving traffic and coming much closer to VISA/MasterCard processing volumes.

I cannot see a flaw in that.

I would request some background data here: which nodes had a node sent its transactions to before TF was introduced? To each it is connected to or was there a special selection of nodes?

2. Blocks can be generated in advance and sent to most of the miners before they become valid (timestamp validation), thus greatly reducing rate of orphaned blocks.

So, when does this process happen?

When there are more transactions to be included in the current block than the block's maximum number of transactions would allow, right?

3. Due to ability to predict timestamps of future blocks (rate of blocks) it becomes possible to set appropriate fees to assure quick confirmations for important transactions (without paying too much for inclusion into a block).

That relates to my question about 2. How is consensus reached on which transactions are included when there are more than the block's max would allow?

Couldn't it be possible that nodes simply agree on not verifying a specific transaction and therefore excluding accounts from transferring NXT.

It has a certain similarity to OS scheduling (processor = block and has limited capacity to handle ops). Some processes are indeed more important and deserve more processing time but starving processes should be avoided as well no matter how small its priority is.

My conclusion here in case of TF, higher fee = higher priority and greedy behavior of forgers:
Bad Trudy knows the forgers in advance. So, it sends her big priority transactions to these nodes and therefore preventing the verification of other transactions.

One solution is therefore to increase the block's maximum number of transactions so far that makes it practically impossible to incent a forger to only forge Trudy's transactions.

And the most important feature:
The network can detect which miners don't take part in block generation and act accordingly.

The last point deserves to be described with more details.

Imagine someone is going to do a "51%" attack against Nxt and he owns 90% of all coins. The adversary must stop generating blocks for legit branch coz he won't be able to compete against 100% mining power with his 90%.

I don not understand that. If he has 90%, why does he need to compete against 100% and not 10%?

So he decides to "skip" his turn to generate a block. The rest 10% of the network detects this and penalizes the adversary by setting his mining power to 0 and distributing it among other miners. Now the network is back to 100% power coz everyone got 10-fold increase. The adversary can mine other branch in a secret place but it won't be able to replace the legit branch. Of course, the 2nd branch will have 100% "hashing" power tied to it as well, coz the attacker will get his 90% bumped to 100% but this can be counteracted by some mechanisms of advanced consensus (still not revealed).

Why just skipping? Couldn't a 90%-forger do much more evil things? Why not rejecting some transactions? Or verifying only its own?

Maybe, you can elaborate more one this.

As a 100% PoS currency Nxt is protected against a government wealthy entity that could buy/produce a lot of ASICs, with the transparent mining it's protected even against someone buying most of the coins.

Protected against not-creating a block.

So, what does make Nxt a really next-gen currency? Not those nice features like decentralized exchange, or decentralized DNS, or decentralized app store. The transparent mining algo does, and this is only the 1st part of BCNext's plan...

Edit: BCNext pointed out that I forgot to mention Selfish Mining. Sorry. Transparent mining solves the selfish mining issue completely. Dixi.

Let me get this straight:

Every account (call it X) in the network is able to determine which other account (call it Y) in the visible network should forge the next block, right? If Y refuses to do so, X will penalize Y as that, X won't consider Y forging the next 1440 blocks. I think I got that.
What about accounts outside of the perspective of X? They are practically not forging from the perspective of X.
There could be an account (call it Z) X have no awareness of and will get the forged block of Z via its peers. Because the peers P are trustworthy, X will only get a block from Z if Z forged a block when it was supposed to in the eyes of P. So far, so good.

What if, the peers aren't trustworthy? What if Z is only visible to its fellow peers and the peers function as a intermediate to Z?

Like in "I am sorry, I am late, but Z forged its block on time. I mean all this network latency and the intermediate nodes between Z and me. Took some time, but we finally managed to get the block to me and NOW you get it, too, my dear X."

[Cryddit]

Cryddit already showed that forging is ok - https://bitcointalk.org/index.php?topic=364218.msg4861016#msg4861016

That's a fine example of how we fail to communicate.  I thought I was demonstrating the scope and extent of the problem in a more realistic setup and you thought I was showing that it was okay. 

Whatever, it's your call.  Decisions about NXT don't affect me at all anymore.

I think I'm going to drop out of this topic; it annoys me.

[Come-from-Beyond]

That's a fine example of how we fail to communicate.  I thought I was demonstrating the scope and extent of the problem in a more realistic setup and you thought I was showing that it was okay. 

Whatever, it's your call.  Decisions about NXT don't affect me at all anymore.

I think I'm going to drop out of this topic; it annoys me.

Actually u proved my point of view. 

[Adrian-x]

I was sent here from one of the NXT forums, and after reading the past 12 pages I have a greater understanding but I still lack some basics.

Thanks in advance for your explanation.

How does the NXT blockchain work, does it grow in the same way as Bitcoin or is there an alternate storage distribution?

[Come-from-Beyond]

How does the NXT blockchain work, does it grow in the same way as Bitcoin or is there an alternate storage distribution?

The same as Bitcoin.

[Adrian-x]

How does the NXT blockchain work, does it grow in the same way as Bitcoin or is there an alternate storage distribution?

The same as Bitcoin.

Thanks, as higher transaction speeds are possible due to predetermined mining nodes, one would expect the blockchain to grow faster than Bitcoin. Are there any ideas on how to distribute a super large blockchain while keeping it decentralized?

Or incentives decentralized hosting?

[Come-from-Beyond]

Thanks, as higher transaction speeds are possible due to predetermined mining nodes, one would expect the blockchain to grow faster than Bitcoin. Are there any ideas on how to distribute a super large blockchain while keeping it decentralized?

Or incentives decentralized hosting?

Few days ago I downloaded Elder Scrolls Online beta client, its size was 25 GiB. I don't think 10 GiB per day is a really big problem.

[Adrian-x]

Thanks, as higher transaction speeds are possible due to predetermined mining nodes, one would expect the blockchain to grow faster than Bitcoin. Are there any ideas on how to distribute a super large blockchain while keeping it decentralized?

Or incentives decentralized hosting?

Few days ago I downloaded Elder Scrolls Online beta client, its size was 25 GiB. I don't think 10 GiB per day is a really big problem.

Not now but I it's potentially an uncertain variable I'd like to see addressed in an altcoin.

[ManDrone]

There was a comment in this thread from a while back that got buried due to the poster being kind of a dick about the answer he got, but it was the reason I read through the whole thread to begin with, so I hope to get some clarification here...

Regarding transparent mining, and the ability to know the source of the next forged block: If a bad agent wants to attack the system, knowing the IP of the forger(s) seems like a ripe place for continuous DDOS attacks against unprotected victims. The prior answer was "forgers can use the Tor network" but that seems like a huge stretch to adoption as 99% of people don't know what that means much less how to set that up. Is that the real answer to this issue (assuming it is an "issue" to begin with)?

Thanks in advance.

[Come-from-Beyond]

There was a comment in this thread from a while back that got buried due to the poster being kind of a dick about the answer he got, but it was the reason I read through the whole thread to begin with, so I hope to get some clarification here...

Regarding transparent mining, and the ability to know the source of the next forged block: If a bad agent wants to attack the system, knowing the IP of the forger(s) seems like a ripe place for continuous DDOS attacks against unprotected victims. The prior answer was "forgers can use the Tor network" but that seems like a huge stretch to adoption as 99% of people don't know what that means much less how to set that up. Is that the real answer to this issue (assuming it is an "issue" to begin with)?

Thanks in advance.

It's not an issue for specialized hubs that forge blocks using leased forging power.

[ManDrone]

There was a comment in this thread from a while back that got buried due to the poster being kind of a dick about the answer he got, but it was the reason I read through the whole thread to begin with, so I hope to get some clarification here...

Regarding transparent mining, and the ability to know the source of the next forged block: If a bad agent wants to attack the system, knowing the IP of the forger(s) seems like a ripe place for continuous DDOS attacks against unprotected victims. The prior answer was "forgers can use the Tor network" but that seems like a huge stretch to adoption as 99% of people don't know what that means much less how to set that up. Is that the real answer to this issue (assuming it is an "issue" to begin with)?

Thanks in advance.

It's not an issue for specialized hubs that forge blocks using leased forging power.

But most people with NXT will not have that... so how does this play out in the wild? 99 DDoS attacks on random victims who have NXT on their cell phone (and were supposed to forge the next block) and then the 100th is a hub so protected and the block gets forged? Also, what happens to the transactions that are being sent to DDoS IP addresses during the DDoS (or is that a non-issue due to the block never being forged with that IP)?

[Come-from-Beyond]

But most people with NXT will not have that... so how does this play out in the wild? 99 DDoS attacks on random victims who have NXT on their cell phone (and were supposed to forge the next block) and then the 100th is a hub so protected and the block gets forged? Also, what happens to the transactions that are being sent to DDoS IP addresses during the DDoS (or is that a non-issue due to the block never being forged with that IP)?

Those 99 ppl will lease forging power to the hub. The hub will be paying part of the fees back to their accounts.

[ManDrone]

But most people with NXT will not have that... so how does this play out in the wild? 99 DDoS attacks on random victims who have NXT on their cell phone (and were supposed to forge the next block) and then the 100th is a hub so protected and the block gets forged? Also, what happens to the transactions that are being sent to DDoS IP addresses during the DDoS (or is that a non-issue due to the block never being forged with that IP)?

Those 99 ppl will lease forging power to the hub. The hub will be paying part of the fees back to their accounts.

So it sounds like everyone(?) is behind this "umbrella" of protection from a hub. Who owns a hub? Is the forging based then on the "hub level" IP? Do people choose which hub to be a part of or is it proximity based or...? Very new to this, so hope these aren't old questions (I'm familiar with traditional cryptos, just not his one).

[Come-from-Beyond]

So it sounds like everyone(?) is behind this "umbrella" of protection from a hub. Who owns a hub? Is the forging based then on the "hub level" IP? Do people choose which hub to be a part of or is it proximity based or...? Very new to this, so hope these aren't old questions (I'm familiar with traditional cryptos, just not his one).

Anyone who can afford to pay for antiDDoS protection can own a hub. People do choose hub(s) to lease forging power to. To keep the network as decentralized as possible they could split forging power to 100 parts and lease to 100 different hubs.

[ManDrone]

So it sounds like everyone(?) is behind this "umbrella" of protection from a hub. Who owns a hub? Is the forging based then on the "hub level" IP? Do people choose which hub to be a part of or is it proximity based or...? Very new to this, so hope these aren't old questions (I'm familiar with traditional cryptos, just not his one).

Anyone who can afford to pay for antiDDoS protection can own a hub. People do choose hub(s) to lease forging power to. To keep the network as decentralized as possible they could split forging power to 100 parts and lease to 100 different hubs.

So the perceived overall/network (not personal) advantage of transparent forging (as opposed to secret forging) is that the speeding up of the confirmations due to knowing where to send transaction details to trumps the headache for the common man of trying to disentangle the technical stuff required to "lease" their CPU power to a "hub" and the consequences of most naive users not bothering to lease (due to ignorance, laziness, don't-have-to-do-this-for-any-other-crypto-ness)? This seems like a serious barrier to entry for the (future) common user. How would grandma know to do any of this shit when she just wants to use the NXT crypto like she uses her Bitcoins (this is me imagining the future)? It seems by not being part of a leased pool she may be subject to a DDoS at worst (her turn to forge is up and some bad actor is blasting her IP) and at best will never get any "forging" interest (because she is not part of a hub).

If I am correct, don't the NXT devs see this as a (serious) barrier to adoption? I have a background in psychology/usability/user experience so these "common man's experience" scenarios I ask about are how I approach a lot of new technology. The fact that there is a technical solution to an issue does not mean the issue disappears (e.g. protecting accounts with passwords).

Not trying to be combative or annoying, just trying to understand.

[Come-from-Beyond]

So the perceived overall/network (not personal) advantage of transparent forging (as opposed to secret forging) is that the speeding up of the confirmations due to knowing where to send transaction details to trumps the headache for the common man of trying to disentangle the technical stuff required to "lease" their CPU power to a "hub" and the consequences of most naive users not bothering to lease (due to ignorance, laziness, don't-have-to-do-this-for-any-other-crypto-ness)? This seems like a serious barrier to entry for the (future) common user. How would grandma know to do any of this shit when she just wants to use the NXT crypto like she uses her Bitcoins (this is me imagining the future)? It seems by not being part of a leased pool she may be subject to a DDoS at worst (her turn to forge is up and some bad actor is blasting her IP) and at best will never get any "forging" interest (because she is not part of a hub).

If I am correct, don't the NXT devs see this as a (serious) barrier to adoption? I have a background in psychology/usability/user experience so these "common man's experience" scenarios I ask about are how I approach a lot of new technology. The fact that there is a technical solution to an issue does not mean the issue disappears (e.g. protecting accounts with passwords).

Not trying to be combative or annoying, just trying to understand.

Nxt doesn't care about someone not forging/leasing. It just sets their forging power to zero and bumps total forging power of the others to 100%. So no problem here.

[ManDrone]

So the perceived overall/network (not personal) advantage of transparent forging (as opposed to secret forging) is that the speeding up of the confirmations due to knowing where to send transaction details to trumps the headache for the common man of trying to disentangle the technical stuff required to "lease" their CPU power to a "hub" and the consequences of most naive users not bothering to lease (due to ignorance, laziness, don't-have-to-do-this-for-any-other-crypto-ness)? This seems like a serious barrier to entry for the (future) common user. How would grandma know to do any of this shit when she just wants to use the NXT crypto like she uses her Bitcoins (this is me imagining the future)? It seems by not being part of a leased pool she may be subject to a DDoS at worst (her turn to forge is up and some bad actor is blasting her IP) and at best will never get any "forging" interest (because she is not part of a hub).

If I am correct, don't the NXT devs see this as a (serious) barrier to adoption? I have a background in psychology/usability/user experience so these "common man's experience" scenarios I ask about are how I approach a lot of new technology. The fact that there is a technical solution to an issue does not mean the issue disappears (e.g. protecting accounts with passwords).

Not trying to be combative or annoying, just trying to understand.

Nxt doesn't care about someone not forging/leasing. It just sets their forging power to zero and bumps total forging power of the others to 100%. So no problem here.

Nextcoin Motto: "NextCoin... Forge it if you are savvy, just use it if you aren't."

I guess you could replace "forge" with "mine" for other coins, so not a big deal in the end.

[ZeroTheGreat]

It's actually a big deal: mining "blackholed", forging is not.

Common sense doesn't apply to cryptocurrencies so easy, cos its completely revolutionary technology. Decentralized consensus.

[Come-from-Beyond]

What protection exists in the Transparent Forging mechanism to prevent a large account holder with a clock set fast from forging before someone else (on a regular basis), and thus inflicting a 1440 block lockout on other accounts?

Blocks with timestamp too far in the future r ignored.

[Come-from-Beyond]

What protection exists in the Transparent Forging mechanism to prevent a large account holder with a clock set fast from forging before someone else (on a regular basis), and thus inflicting a 1440 block lockout on other accounts?

Blocks with timestamp too far in the future r ignored.

But what if it was just short enough to be accepted (say 2-5 seconds ahead?), and other account on synchronized UTC time?

Reason I ask is my forging of blocks lately has been nowhere near the expected rate (even if all 1B active), and some larger accounts seem to be getting a much larger ratio than expected.

Just trying to figure out why...

8 of last 17 blocks on explorer forged by 4747512364439223888 with 5% stake (50MIL).  As of block 66890

Nothing strange, he is the only guy who work hard forging.

[Come-from-Beyond]

Apologies for the skepticism.  Something weird looks to be going on with the target percentages where they are and the stake percentages.

What analysis has been done to craft against a early block injection?  And, specifically, would another forger be penalized for being 'late'?

edit: And, this is not a question about envy...  It's about a possibility for a malicious majority stake attack (could be much less than 51%) which is able to penalize other peers from forging and thus gaining defacto control of the blockchain.  The point about 'early clock timing' was just one scenario which I could envision.

Block sequence is pre-determined. U can't inject a block earlier than u r doomed to do so.

[Lohoris]

In Nxt this problem doesn't arise coz all participants (miners) r known.

I came to know about NXT and I found its entirely proof-of-stake design very attractive, so I'm reading documentation.

I would like to also spread the word about it, but I'm a bit concerned about linking a site which is supposed to have a technical explaination, when it's written with these cool-youngster abbreviations.

Could you please edit the post in proper English?

If you want, I can fix it myself and you just copy-paste it into your post (though it would be better if a native speaker did that).

Thanks for your consideration.

[Lohoris]

Of course, the 2nd branch will have 100% "hashing" power tied to it as well, coz the attacker will get his 90% bumped to 100% but this can be counteracted by some mechanisms of advanced consensus (still not revealed).

This is the weakest link of this whole document.
What does "not revealed" imply?
I mean, I can't convince people to trust this, if some vital details are not revealed...

[bitcoinpaul]

TF isn't fully implemented yet. The current TF can be reviewed in the source code, which is publicly available. Full TF will be implemented the next weeks.

[bytemaster]

I am trying to understand how transparent forging can get a secure random number to select the forger deterministically.

If the forger is selected and punished if they don't produce the block, then this means that they cannot be 'mining' and that their selection must be derived from data in the block chain.  If the forger can control the data they put in the block chain when they 'forge', then it seems like they would have control over who got picked next. 

[mczarnek]

I just figured out how to choose a random number deterministically within a decentralized network, where someone with 90% of the forging power as determined by proof of stake could only get lucky enough to manipulate this number 1 in a billion years at a rate of 1 block per minute.  It would only require 300 forgers online, we currently have more than this.  If we have get 500 forgers participating this number drops to someone with 90% of the forging power only getting lucky enough 1 in approximately 40 Octillion years.

And it scales nicely and it's fast, could easily be done. No proof of work required.  Could probably cut down how long you lock up funds and changes to forging power to 10 blocks, say 60 if you want to be safe. I'm telling you, it's big.  Already run it by one person, would like to run it by others.

If I were working for Nxt it'd be a different story but I don't want to just put the whole idea if I can get a bounty on it.  If I can proof this, is there a bounty on it?  Or you guys already have a work around in mind that could achieve this?

[ysbysb2000]

BTC   haha

[benjyz]

I am trying to understand how transparent forging can get a secure random number to select the forger deterministically.

If the forger is selected and punished if they don't produce the block, then this means that they cannot be 'mining' and that their selection must be derived from data in the block chain.  If the forger can control the data they put in the block chain when they 'forge', then it seems like they would have control over who got picked next. 

any answers to this?

[bytemaster]

I am trying to understand how transparent forging can get a secure random number to select the forger deterministically.

If the forger is selected and punished if they don't produce the block, then this means that they cannot be 'mining' and that their selection must be derived from data in the block chain.  If the forger can control the data they put in the block chain when they 'forge', then it seems like they would have control over who got picked next. 

any answers to this?

I believe the network requires forgers to submit a hash(secret) in advance and reveal their secret when they produce a block.  This creates a chain of secrets that cannot be cheated.

[delulo]

The rest 10% of the network detects this and penalizes the adversary by setting his mining power to 0 and distributing it among other miners.

How is this (...penalizing...) possible?

[bytemaster]

The rest 10% of the network detects this and penalizes the adversary by setting his mining power to 0 and distributing it among other miners.

How is this (...penalizing...) possible?

It would be like kicking out a delegate for 1 round every time he misses a block. 

[delulo]

The rest 10% of the network detects this and penalizes the adversary by setting his mining power to 0 and distributing it among other miners.

How is this (...penalizing...) possible?

It would be like kicking out a delegate for 1 round every time he misses a block.  

Where does the central authority come from who can kick him out? Or are we simpy talking about a fork here which should be possible no matter how much stake the attacker has bough?

If it is no fork how can the delegate / the bad stack be voted out if the bad stake has 90%?

My quote was form the 90% attack resistance part of the OP:

Imagine someone is going to do a "51%" attack against Nxt and he owns 90% of all coins. The adversary must stop generating blocks for legit branch coz he won't be able to compete against 100% mining power with his 90%. So he decides to "skip" his turn to generate a block. The rest 10% of the network detects this and penalizes the adversary by setting his mining power to 0 and distributing it among other miners. Now the network is back to 100% power coz everyone got 10-fold increase. The adversary can mine other branch in a secret place but it won't be able to replace the legit branch. Of course, the 2nd branch will have 100% "hashing" power tied to it as well, coz the attacker will get his 90% bumped to 100% but this can be counteracted by some mechanisms of advanced consensus (still not revealed).