Bitcoin Forum
April 04, 2020, 02:36:48 AM *
News: Latest Bitcoin Core release: 0.19.1 [Torrent]
 
   Home   Help Search Login Register More  
Poll
Question: Bitcoin fork proposal by respected Bitcoin lead dev Gavin Andresen, to increase the block size from 1MB to 20MB.
pro
anti
agnostic
DGAF

Pages: « 1 ... 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 [118] 119 120 121 122 123 124 125 126 127 128 129 130 131 »
  Print  
Author Topic: Bitcoin 20MB Fork  (Read 154258 times)
davout
Legendary
*
Offline Offline

Activity: 1372
Merit: 1002


1davout


View Profile WWW
March 12, 2015, 06:37:39 PM
 #2341

I am not so sure that the cross chain market will even exist. How many confirmations will you request from the small chain after the fork, knowing that the entire history can be rewritten since the fork by malicious miners ?

I can guarantee you that it will exist, long before the fork even happens.

1585967808
Hero Member
*
Offline Offline

Posts: 1585967808

View Profile Personal Message (Offline)

Ignore
1585967808
Reply with quote  #2

1585967808
Report to moderator
1585967808
Hero Member
*
Offline Offline

Posts: 1585967808

View Profile Personal Message (Offline)

Ignore
1585967808
Reply with quote  #2

1585967808
Report to moderator
Advertised sites are not endorsed by the Bitcoin Forum. They may be unsafe, untrustworthy, or illegal in your jurisdiction. Advertise here.
gentlemand
Legendary
*
Offline Offline

Activity: 2324
Merit: 2417


Welt Am Draht


View Profile
March 12, 2015, 06:40:37 PM
 #2342


Is anybody here from a country where the strawman version of blacklists has actually been implemented against high-denomination currency?  


They have a wonderfully simple system in the UK for handling the £50 note, which is the biggest denomination worth about $75. They are almost 100% impossible to spend. I've only had three pass through my hands and wandered from shop to shop trying to spend them and they just tell you to go away.


Cryddit
Legendary
*
Offline Offline

Activity: 924
Merit: 1044


View Profile
March 12, 2015, 06:41:10 PM
 #2343

Have you noticed that, in the USA, whenever you pay for something with a $50 or $100 bill, the cashier has to record the serial number of the bill?  

really???

well i am in germany and here it is definitely not the case.
and this works? the cashier sends a list to fincen or what? for ANY note he received?

is this immediate? as in the cashier can refuse to take the bill or has to call the police or whatever?

i can pay with a 1000€ bill without the cashier writing down the serial...

sounds unbelieveable
Hah! Our government would never trust us with denominations that large; the biggest bill in circulation in the US is $100. Although larger deniminations have been printed for special purposes in the past, they have never circulated.  

Depending on the store, the cashier may have to write the serial number on a paper list, or may have to scan the bill through a reader.   I don't know whether the blacklist comparison is done by the accepting company, implying that the private sector has the whole black list available, or the list is sent onward to a financial center, implying that the financial centers and/or regulatory agencies have all those transaction records available.  Either implication is somewhat disquieting, but certainly no worse than the publicly readable block chain.  At any rate, I've never seen a real bill rejected on the basis of the comparison.

The only category of "immediate refusal" is if the bill is revealed to be a counterfeit. - something about which we needn't worry with Bitcoin.
hdbuck
Legendary
*
Offline Offline

Activity: 1274
Merit: 1001



View Profile
March 12, 2015, 06:41:51 PM
 #2344

I am not so sure that the cross chain market will even exist. How many confirmations will you request from the small chain after the fork, knowing that the entire history can be rewritten since the fork by malicious miners ?

I can guarantee you that it will exist, long before the fork even happens.

lol this should be fun.

onemorexmr
Sr. Member
****
Offline Offline

Activity: 252
Merit: 250



View Profile
March 12, 2015, 06:43:47 PM
 #2345

The only category of "immediate refusal" is if the bill is revealed to be a counterfeit. - something about which we needn't worry with Bitcoin.

well thats reasonable and acceptable...

how do you buy used cars?
in germany you should buy them with cash, because if the seller claims insolvency after you have paid by SEPA/SWIFT he keeps the car and the cash...

XMR || Monero || monerodice.net || xmr.to || mymonero.com || openalias.org || you think bitcoin is fungible? watch this
danielpbarron
Full Member
***
Offline Offline

Activity: 213
Merit: 100


Daniel P. Barron


View Profile WWW
March 12, 2015, 06:47:06 PM
 #2346

I am not so sure that the cross chain market will even exist. How many confirmations will you request from the small chain after the fork, knowing that the entire history can be rewritten since the fork by malicious miners ?

I can guarantee you that it will exist, long before the fork even happens.

It already does exist. Thanks to things like GPG contracts it shouldn't matter too much that transactions might get nullified delayed longer than usual.

Quote from: #bitcoin-assets
mircea_popescu: ;;sell 1000 "Gavin Scamcoins" @ 750 BTC Future delivery. Larger amounts will get you an even better deal. Smaller amounts may be considered.
gribble: Order id 21921 created.

Hey speaking of which, you derps should put your money where your mouth is! Swing by #bitcoin-assets and ask for mircea_popescu. He will gladly sell you "gigablockcoins" or whatever in exchange for real bitcoin. The odds offered are currently 3:4 (you get 4 scamcoins for every 3 bitcoin paid).

Marriage is a permanent bond (or should be) between a man and a woman. Scripture reveals a man has the freedom to have this marriage bond with more than one woman, if he so desires. But, anything beyond this is a perversion. -- Darwin Fish
hdbuck
Legendary
*
Offline Offline

Activity: 1274
Merit: 1001



View Profile
March 12, 2015, 06:54:44 PM
 #2347

I am not so sure that the cross chain market will even exist. How many confirmations will you request from the small chain after the fork, knowing that the entire history can be rewritten since the fork by malicious miners ?

I can guarantee you that it will exist, long before the fork even happens.

It already does exist. Thanks to things like GPG contracts it shouldn't matter too much that transactions might get nullified delayed longer than usual.

Quote from: #bitcoin-assets
mircea_popescu: ;;sell 1000 "Gavin Scamcoins" @ 750 BTC Future delivery. Larger amounts will get you an even better deal. Smaller amounts may be considered.
gribble: Order id 21921 created.

Hey speaking of which, you derps should put your money where your mouth is! Swing by #bitcoin-assets and ask for mircea_popescu. He will gladly sell you "gigablockcoins" or whatever in exchange for real bitcoin. The odds offered are currently 3:4 (you get 4 scamcoins for every 3 bitcoin paid).




Grin
Cryddit
Legendary
*
Offline Offline

Activity: 924
Merit: 1044


View Profile
March 12, 2015, 06:55:45 PM
 #2348


how do you buy used cars?
in germany you should buy them with cash, because if the seller claims insolvency after you have paid by SEPA/SWIFT he keeps the car and the cash...

When you actually pay for the car (check, cash, credit card) and take possession of it (by driving off the premises) it becomes your property and cannot be claimed by the seller's creditors.

Also, you have a non-performance claim if you are unable to take possession, and can get your money back in court (that is, you are recognized as having the same legal standing as the seller's other creditors). If you pay by credit card or check, this is easy.  Legally, it also applies to cash, but it is less easy to press the claim with cash payments, because records may be conveniently "absent" in that case.

Professional used-car dealers usually have much more involved rituals involving witnessed, signed contracts and cashier's checks or bank transfers.  
danielpbarron
Full Member
***
Offline Offline

Activity: 213
Merit: 100


Daniel P. Barron


View Profile WWW
March 12, 2015, 07:06:42 PM
 #2349

Hey speaking of which, you derps should put your money where your mouth is! Swing by #bitcoin-assets and ask for mircea_popescu. He will gladly sell you "gigablockcoins" or whatever in exchange for real bitcoin. The odds offered are currently 3:4 (you get 4 scamcoins for every 3 bitcoin paid).

What I am reading from this offer is that you pay 3 MPcoin for every Gavincoin bought from MP. Not impressive.

You send 750 BTC to MP now and someday later he will send you 1000 Gavincoin back.
Which means that you pay 750 MPcoin in exchange for 250 Gavincoin.
(Unless the 750 BTC is also "future payment", after the fork, but then he should say it more clearly)

These are good questions. If you are sincerely interested in striking a deal I'm sure MP can answer them. He's active right now; don't be shy!

Marriage is a permanent bond (or should be) between a man and a woman. Scripture reveals a man has the freedom to have this marriage bond with more than one woman, if he so desires. But, anything beyond this is a perversion. -- Darwin Fish
Cryddit
Legendary
*
Offline Offline

Activity: 924
Merit: 1044


View Profile
March 12, 2015, 07:12:53 PM
 #2350


You send 750 BTC to MP now and someday later he will send you 1000 Gavincoin back.
Which means that you pay 750 MPcoin in exchange for 250 Gavincoin.
(Unless the 750 BTC is also "future payment", after the fork, but then he should say it more clearly)

Unless MP is firmly linked to a real-world identity that can be held legally responsible for non-performance, and I personally can prove in court that the counterparty on that IRC channel has the same legal identity, I will not be paying MP, over a fuckin' IRC channel no less, for any promises of any kind.

Come on, guys, we aren't supposed to be idiots.  Why would we deal with anyone via an unauthenticated protocol for future performance or delivery of anything?
RoadStress
Legendary
*
Offline Offline

Activity: 1862
Merit: 1002


View Profile
March 12, 2015, 07:17:51 PM
 #2351

You. Are. Wrong. How many times do I have to explain this you damned dirty government agent.

You are confusing the mechanism by which the fork is triggered, with the economic pressure put on miners afterwards. You are confusing the pre-fork with the post-fork. It costs miners nothing to brand their blocks "version 4," whether they are actually going to adopt the new rules or not. It is an entirely different story when they start minting blocks that other nodes cannot validate. In the post-fork scenario, there will be two different versions of bitcoin for sale at two different prices. Miners will choose the most profitable coin to mine, just like altcoin miners shift around to different pools depending on changing difficulties and prices.

I am sure that 21e6 that just announced a $116M investment round in order to bring mining to the masses will afford a couple of nodes that will support the large block size limit. If you think your boss MP can compete with them then you are simply lying to yourself.

blacklisting people is a different story than blacklisting specific coins.
where you every in a store and heard a cashier saying: no i dont take this coin, please give me another one?

Don't try to change the subject like everyone else. I haven't said anything about blacklisting coins. I said about blacklisting people/addresses. If you re-read my post again you will see that I have already answered to this matter: "Taking into account the history of the coins is simply retarded and will be done only by those that do not understand Bitcoin."

And yes. Since no cashier will ever tell you that it can't accept your money because they were involved in shady stuff the same will happen with Bitcoin.

How about a miner, or a group of miners, broadcast v4 blocks, or even go as far as actually playing along with the fork, for the sole purpose of artificially inflating the exchange rate of gavincoin?
For an actor, or a group, with a reasonable chunk of hashpower, that would be a pretty efficient way to manipulate the cross-chain market and make a killing in the process.

I thought that at least 75% of the hashpower is needed in order to be able to broadcast v4 blocks so I don't see how can a miner or a group of miners can play along with the fork. Maybe you can explain it to me.

Come on, guys, we aren't supposed to be idiots.  Why would we deal with anyone via an unauthenticated protocol for future performance or delivery of anything?

Isn't this a case for a smart contract on the blockchain? Both parties put money and when the conditions apply the money goes to either sides and until then nobody has control over the money so nobody can vanish with them.

H/w Hosting Directory & Reputation - https://bitcointalk.org/index.php?topic=622998.0
onemorexmr
Sr. Member
****
Offline Offline

Activity: 252
Merit: 250



View Profile
March 12, 2015, 07:21:13 PM
 #2352

Don't try to change the subject like everyone else. I haven't said anything about blacklisting coins. I said about blacklisting people/addresses. If you re-read my post again you will see that I have already answered to this matter: "Taking into account the history of the coins is simply retarded and will be done only by those that do not understand Bitcoin."


i got confused because you said addresses. blacklisting addresses is imho the same as blacklisting coins.

blacklisting persons can only happen on exchanges (and its already done - see coinbase)

XMR || Monero || monerodice.net || xmr.to || mymonero.com || openalias.org || you think bitcoin is fungible? watch this
danielpbarron
Full Member
***
Offline Offline

Activity: 213
Merit: 100


Daniel P. Barron


View Profile WWW
March 12, 2015, 07:29:29 PM
 #2353


You send 750 BTC to MP now and someday later he will send you 1000 Gavincoin back.
Which means that you pay 750 MPcoin in exchange for 250 Gavincoin.
(Unless the 750 BTC is also "future payment", after the fork, but then he should say it more clearly)

Unless MP is firmly linked to a real-world identity that can be held legally responsible for non-performance, and I personally can prove in court that the counterparty on that IRC channel has the same legal identity, I will not be paying MP, over a fuckin' IRC channel no less, for any promises of any kind.

Come on, guys, we aren't supposed to be idiots.  Why would we deal with anyone via an unauthenticated protocol for future performance or delivery of anything?

What are you even doing with bitcoin? Go play with dollars if that's what you've come to expect. Which protocol is "unauthenticated? IRC? You do realize we use GPG to authorize users right? You can't even speak in the channel unless you have decrypted a password with your key, or been granted voice by someone who already has. There isn't any community on the planet that is more focused on authentication and security than #bitcoin-assets. Why do you think I'm so crazy about promoting it.

That aside, regardless of where the deal is struck, be it on the forum or AOL instant messenger, GPG would still be used to sign the contract. Not that GPG alone is enough to be sure you'll be paid (not that you can ever be 100% sure, even when going through state-sanctioned channels), but we use a Web-of-Trust in order to help keep track of who trusts who. For example, MP has a score of 40 in my L2 (level 2) through 28 connections -- that is, 28 users whom I trust and who may assign a rating from -10 to 10 have rated MP, and those ratings all added up equals 40.

Code:
           [fromnick] => danielpbarron
            [fromkey] => 155934BDD16E8EAF4493CB9CB36AE9849D961AC9
            [tonick] => mircea_popescu
            [tokey] => 6160E1CAC8A3C52966FD76998A736F0E2FB7B452
            [level1trust] => 8
            [level2trust] => 40
            [level2connections] => 28
            [ratedsince] => 22-Jul-2011

You just need to get in the WoT, rate the people you trust, and see if he shows up in your L2. Maybe you can talk him into using a 3rd party as escrow -- perhaps nanotube.



You. Are. Wrong. How many times do I have to explain this you damned dirty government agent.

You are confusing the mechanism by which the fork is triggered, with the economic pressure put on miners afterwards. You are confusing the pre-fork with the post-fork. It costs miners nothing to brand their blocks "version 4," whether they are actually going to adopt the new rules or not. It is an entirely different story when they start minting blocks that other nodes cannot validate. In the post-fork scenario, there will be two different versions of bitcoin for sale at two different prices. Miners will choose the most profitable coin to mine, just like altcoin miners shift around to different pools depending on changing difficulties and prices.

I am sure that 21e6 that just announced a $116M investment round in order to bring mining to the masses will afford a couple of nodes that will support the large block size limit. If you think your boss MP can compete with them then you are simply lying to yourself.

That's not real money. That 116 million exists only for the purpose of pretending to invest in derpy startups. It can't be used to buy real things like massages and dinners.

Quote from: Pete Dushenski
This is assuming that we’re talking about like things here. Despite the superficial appearance that “dollars are dollars,” I’m talking about TideUSD and you’re talking about BezzleUSD. The former can be used to purchase goods and services, such as foot massages and brunch with friends, while the latter is only useful for buying Instagram, WhatsApp, etc. at prices so inflated that hot air balloons are jealous. Not only are Facebook’s profits unusable in the real world and the ultimately product of so much Fed printing, but just as was the case with Bernie Madoff, every last penny Facebook “earns” is entirely fraudulent.

Marriage is a permanent bond (or should be) between a man and a woman. Scripture reveals a man has the freedom to have this marriage bond with more than one woman, if he so desires. But, anything beyond this is a perversion. -- Darwin Fish
stevenh512
Full Member
***
Offline Offline

Activity: 137
Merit: 100



View Profile
March 12, 2015, 07:35:48 PM
 #2354

Have you noticed that, in the USA, whenever you pay for something with a $50 or $100 bill, the cashier has to record the serial number of the bill?  

I live in the U.S. and use $50 and $100 bills quite often and I've never had a cashier at any store or a teller at any bank write down the serial number.

Quote
Guess what?  Those serial numbers are being compared to a 'blacklist' of bills known to be counterfeited, stolen, or otherwise involved in crimes.  So, no, I don't think blacklisting will affect bitcoin fungibility substantially more than it already affects dollar fungibility.  

While there may or may not be such a 'blacklist' (and I'm not claiming to know whether or not such a thing exists), there are much easier ways to detect counterfeit U.S. currency. Two that come to mind immediately are UV light (blacklight) and the "counterfeit detecting" pens. As far as bills that were used in a crime, if a bill was used in a crime that doesn't necessarily mean that I had anything to do with that crime simply because that bill, through normal circulation, ended up in my wallet. If those bills were indeed 'blacklisted' they would be taken out of circulation whenever they reach a bank rather than being put back into circulation to possibly punish innocent people just because someone might have used them in a crime at some point in the past.

While I don't deny the possibility of such a 'blacklist' I've never seen any evidence of it personally (such as store cashiers or bank tellers writing down serial numbers or checking against a list) and it would be the least efficient and most error prone way possible to accomplish the goals that you claim the 'blacklist' accomplishes considering the alternatives.

Quote
Is anybody here from a country where the strawman version of blacklists has actually been implemented against high-denomination currency?  

According to you, that version of blacklists already exists in the U.S. since you claim there are certain $50 and $100 bills which are blacklisted because they are known to be counterfeit, stolen or used in a crime. If they're blacklisted and people are genuinely checking against this blacklist then the possibility certainly exists that if you were to come across one of those bills you wouldn't be able to spend it.

This signature intentionally left blank.
tvbcof
Legendary
*
Online Online

Activity: 3150
Merit: 1079


View Profile
March 12, 2015, 07:54:05 PM
Last edit: March 12, 2015, 11:34:44 PM by tvbcof
 #2355

Don't try to change the subject like everyone else. I haven't said anything about blacklisting coins. I said about blacklisting people/addresses. If you re-read my post again you will see that I have already answered to this matter: "Taking into account the history of the coins is simply retarded and will be done only by those that do not understand Bitcoin."


i got confused because you said addresses. blacklisting addresses is imho the same as blacklisting coins.

blacklisting persons can only happen on exchanges (and its already done - see coinbase)

The most successful attack would probably be whitelisting rather than blacklisting.  Whitelisting is synonymous with licensing or at least closely related.

To make maple syrup, one takes a bunch of tree sap which is nearly impalpable and slowly cook it down until is is of a suitable form to use on waffles.  This slow consolidation until a body consists of higher valued players who can be pressured is exactly what I see as the most viable form of setup for a successful attack, and matches fairly well a 20x increase then subsequent doublings in block size as is the current proposal.  It results in a corresponding slow 'boiling off' of smaller value support infrastructure.

The key balance here would be to work slowly.  Right now Bitcoin is not a significant threat to almost anyone so there is time.  It's more important to preserve Bitcoin's primacy in the space than it is to forcible destroy it because sudden moves will panic the herd into alternate solutions, and many of these could be much more challenging to attack both because of numbers and different designs.

I've not mentioned the likely effectiveness of attacks on fungibility for some time so I will do so again here.  Please note that an attack such as telling TigerDirect that they must follow a licensing regime would have broad ramifications across the space.  I personally am very much against loss of fungibility on philosophical and economic grounds, but I'm still going to personally de-value a 'tainted' coin.  That is, a spend which is not usable at TigerDirect because it's history cannot be traced through licensed transference.

Edit:  Note that I have no interest in spending my BTC at TigerDirect, but I still de-value BTC which cannot be spent there.  Why?  Because the guy I try to pay with them himself may wish to spend them at TigerDirect and they will be worth less to him.  Fairly simple economics.

Nobody has really made a credible argument to me that the U.S. govt could not or would not require Bitcoin users, and especially of those at the corporate retail level, to adhere to licensing (and thus implement the aformentioned fungibility attack.)  I personally see it as modestly trivial and some moves in that direction happening already.  Were I contracted by Uncle Sam to design an attack on Bitcoin, I would certainly employ the attack I mentioned, and I absolutely would not pull the trigger prematurely.  Today, especially prior to Gavin's hard fork, is very premature.


Cryddit
Legendary
*
Offline Offline

Activity: 924
Merit: 1044


View Profile
March 12, 2015, 08:05:20 PM
 #2356

Have you noticed that, in the USA, whenever you pay for something with a $50 or $100 bill, the cashier has to record the serial number of the bill?  

I live in the U.S. and use $50 and $100 bills quite often and I've never had a cashier at any store or a teller at any bank write down the serial number.


Interesting.  I see it all the time.  Start watching and look for it; I'll be interested to hear if actual observation agrees with your impression, then if it does I'll ask which state you live in.

Quote
Quote
Guess what?  Those serial numbers are being compared to a 'blacklist' of bills known to be counterfeited, stolen, or otherwise involved in crimes.  So, no, I don't think blacklisting will affect bitcoin fungibility substantially more than it already affects dollar fungibility.  

While there may or may not be such a 'blacklist' (and I'm not claiming to know whether or not such a thing exists), there are much easier ways to detect counterfeit U.S. currency. Two that come to mind immediately are UV light (blacklight) and the "counterfeit detecting" pens. As far as bills that were used in a crime, if a bill was used in a crime that doesn't necessarily mean that I had anything to do with that crime simply because that bill, through normal circulation, ended up in my wallet.

Exactly.  That's why they DON'T stop you from spending the bill, even though they have to track its circulation.  They stop people from spending counterfeits, but not from spending bills that were stolen from somebody six months ago or used in a drug deal six weeks ago.  They want to know where these bills are circulating because it's a clue where the crooks are - but they're not trying to stop individual bills.

Quote
According to you, that version of blacklists already exists in the U.S. since you claim there are certain $50 and $100 bills which are blacklisted because they are known to be counterfeit, stolen or used in a crime. If they're blacklisted and people are genuinely checking against this blacklist then the possibility certainly exists that if you were to come across one of those bills you wouldn't be able to spend it.

No.  The strawman version is where the store actually REFUSES your bill because it's on the list, and outside of actual counterfeits I've never seen that.  What I've seen is grocery store clerks have to write down the serial numbers on a clipboard and, because that's a pain in the ass for them, are happier if you pay with smaller bills - not because there's any risk that the larger bills won't be accepted at the bank, but just because writing down the serials is extra work.  
DeathAndTaxes
Donator
Legendary
*
Offline Offline

Activity: 1218
Merit: 1007


Gerald Davis


View Profile
March 12, 2015, 08:27:36 PM
Last edit: March 12, 2015, 09:23:39 PM by DeathAndTaxes
 #2357

(*) : I don't know why Gavin's proposal is to fork at 80% of hashing power, when the other hard forks happened or will happen at 95%. I think it's a mistake since with 20% of the hashrate, MPcoin could have a serious chance to survive for some time, when with 5% it will surely die within days, if not hours, after the fork.

The prior forks did not happen at the 95% threshold, the changes were enforced starting at the 75% threshold.  There were two thresholds (75%/95%) to provide a two stage commit.  The reason for this is that the 75% threshold requires continually monitoring the prior 1000 blocks and it doesn't disallow older block version.  This provides a good upgrade path which minimizes disruptions but it requires continually monitoring the rolling percentage into perpetuity.  The second commit obsoletes old versions and removes the need to computing the rolling percentage (because if going forward all older version blocks are rejected then 100% of future blocks will be the new version).   So you get the best of both worlds but it really only makes sense for soft forks.   Remember is a soft fork new block versions are still valid to older nodes because they add new rules they don't remove or change existing ones.  A v3, v2, or v1 block all look identical to a client which only understands v1 rules.  It also has the added bonus of notifying the client 'hey there are newer rules you probably want to know about' in a decentralized manner.

As an example the block height was added to the coinbase field for v2 blocks.  While the % of v2 blocks on the network was <75% you could make a v2 block, not put the block height in the coinbase field and it would still be valid.   There would be no reason to do this and you would need to write new software which explicitly violates the BIP (because all existing software would be using v1) while changing the version.  It wouldn't happen accidentally but you could do it and the network would accept the block just fine (as long as it was at least valid for v1 rules).   As a side note, since nodes are unaware of future versions that also means right now you could mine a new block with version 1,837,888 an it wouldn't be rejected (as long as it otherwise follows current consensus rules).  If nodes are unaware of a new version but the block is still valid under the version they know they will validate it using their existing rules.  So miners can choose to start putting height in the coinbase field and they can indicate that support by using v2 in the version field.  They can't however force other miners to do the same thing.  The cool part is that since existing nodes also see these newer blocks as valid they have no risk in making the change.  

However once the rolling percentage reaches >75% with a version of 2, any v2 block without the height in the coinbase field would be rejected.  This is a pretty small risk because existing software would still be using v1 as the block version.   One would need to make new software intentionally use v2 as the block version and violate the BIP by not including the block height.   If you did all that your blocks would be fine when the rolling percentage was less than 75% but once it was 75% or more it would be rejected.  Most miners that were not 'v2 aware' would still be using v1 as the block version and with the rolling percentage less than 95% v1 blocks (with or without height in coinbase) would be valid.  'Bad v2' blocks (no height in coinbase) would be the only ones rejected.  This is what allows a safe and seamless upgrade path.  It allows miners to support a new change while at the same time avoiding a split in the network.  Only once the 'laggards' are such a small number that they are the only ones with something to lose is the update enforced.

So at this point the block height checking would be enforced but miners could 'opt out' by mining older version (v1) blocks.   This dynamic only exists for soft forks.  Existing nodes would treat v2 block coinbase fields just as the do v1 coinbase fields (unverified string).  This means to a v1 node it doesn't matter if the coinbase contains a height or not because the whole field is just ignored (for the most part).  In a hard fork an older node can't just 'ignore' that a block is greater than MAX_BLOCK_SIZE constraint.  So there is no way it can accept it unless it has been updated to consensus rules which are aware of the new version.  There is one major disadvantage so far.  If we only had a single commit all miners going forward would have to check the rolling percentage of block versions to know if the height is enforced in future blocks.  It could be enforced in one block, not enforced in the next three, then enforced for the next 400,000 and then suddenly not enforced all depending on how many v1 blocks are mined recently.   Obviously not a good idea to have future validation rules being dynamic for no reasons.  So to avoid that there is a second stage commit, once 95% of the rolling percentage is v2 blocks then v1 blocks are invalid as well.  At this point v2 blocks without height are already invalid and now any v1 block is invalid as well.  That means going forward all valid blocks will be both v2 and have the correct height in the coinbase field.  The nice thing is once that happens all the future logic can be simplified to enforcing the new standard (version number and new rules) on all blocks after the 95% threshold happens which makes the code simpler and reduces the risk of an accidental network split.  For v2 blocks that happened in block 227,835.  If you check the blockchain, all the blocks after 227,835 are v2 and all of them have correct height in the coinbase field.

Right now the same thing is playing out with v3 blocks that will eventually enforce strict DER encoding of signatures (BIP 66).
If <75% of prior blocks are v3 then DER encoding is not enforced on v3 blocks (yes right now a v3 block with non-canonical encoding would still be valid).
If >75% of prior blocks are v3 then DER encoding is enforced on v3 blocks (but one can still use non-canonical encoding on v2 blocks).
If >95% of prior blocks are v3 then v2 blocks are rejected (so all future blocks will be both v3 and have canonical encoding of signatures).

The two stage commit doesn't really apply for hard forks however.   With a hard fork you are altering existing rules not just adding new rules.   This means that older nodes will see the new block as invalid.   Not because it has a different version but because it violates an existing rule.  Once the network forks it is committed regardless.  If block 555,555 is 1.1MB then it will never be valid on existing nodes, it doesn't matter if that is the only block on its chain above 1MB and the next million blocks are all smaller because the entire chain is invalid to existing nodes.  As for why 80% vs 75%?   Well I am not sure 80% has been decided in stone, the whole thing is just a proposal at this point.  Maybe Gavin can comment, I would assume he went with a higher threshold since it is the first hard fork.
solex
Legendary
*
Offline Offline

Activity: 1078
Merit: 1000


100 satoshis -> ISO code


View Profile
March 12, 2015, 08:48:47 PM
 #2358



Right now the same thing is happening w/ strict DER encoding of signatures (BIP 66).
If <75% of prior blocks are v3 then DER encoding is not enforced on v3 blocks.
If >75% of prior blocks are v3 then DER encoding is enforced on v3 blocks (but one can still use non-canonical encoding on v2 blocks).
If >95% of prior blocks are v3 then v2 blocks are rejected.

It is a very cool method for consensus upgrades.
And, for general info, this is a graphical representation of the version 3 block roll-out in progress.

danielpbarron
Full Member
***
Offline Offline

Activity: 213
Merit: 100


Daniel P. Barron


View Profile WWW
March 12, 2015, 08:54:51 PM
 #2359

Hey speaking of which, you derps should put your money where your mouth is! Swing by #bitcoin-assets and ask for mircea_popescu. He will gladly sell you "gigablockcoins" or whatever in exchange for real bitcoin. The odds offered are currently 3:4 (you get 4 scamcoins for every 3 bitcoin paid).

What I am reading from this offer is that you pay 3 MPcoin for every Gavincoin bought from MP. Not impressive.

You send 750 BTC to MP now and someday later he will send you 1000 Gavincoin back.
Which means that you pay 750 MPcoin in exchange for 250 Gavincoin.
(Unless the 750 BTC is also "future payment", after the fork, but then he should say it more clearly)

I asked, and you are correct. My bad.

Quote from: #bitcoin-assets
danielpbarron: http://log.bitcoin-assets.com/?date=21-01-2015#985304 << is the "BTC" side of this to be paid post-fork, because otherwise the deal is really 750 BTC + 750 gavincoin in exchange for 1k gavincoin
assbot: Logged on 21-01-2015 02:32:01; mircea_popescu: ;;sell 1000 "Gavin Scamcoins" @ 750 BTC Future delivery. Larger amounts will get you an even better deal. Smaller amounts may be considered.
mircea_popescu: danielpbarron ahem. through what sort of magic the parts summed exceed the sum ?
danielpbarron: 750 BTC today will be on both chains post-fork
mircea_popescu: right.
danielpbarron: so someone pays you 750 BTC today, which turns into 750 BTC and 750 GSC (gavinscamcoin) later, and you just need to buy another 250 GSC to settle the deal
mircea_popescu: or in other words, they make 250 gsc for no risk, if they believe this theory whereby "people" will "update" to gavincoin on gavin's say so.
danielpbarron: right, it's still a "good deal" to those who are so sure the fork will be a hit; i'm just trying to figure out how "good a deal" it is
danielpbarron: so it's kinda like they are trading 750 BTC for 250 GSC, no?
danielpbarron: where BTC is this "stilly worthless thing" to them
mike_c: danielpbarron: you need to be 75% confident to break even
mike_c: if you are > than that confident in gavincoin, it's a good deal
mike_c: i can do the math for you if it's helpful
danielpbarron: I think I got it now. I was hung up on my own bias against GSC
danielpbarron: in that, I would probably be willing to trade 750 GSC for 250 BTC
mike_c: then you can undercut mp :) quick, make an exchange!
danielpbarron: are you making me an offer?
mike_c: no, i don't sell btc for fiat or for gavincoin.

Marriage is a permanent bond (or should be) between a man and a woman. Scripture reveals a man has the freedom to have this marriage bond with more than one woman, if he so desires. But, anything beyond this is a perversion. -- Darwin Fish
davout
Legendary
*
Offline Offline

Activity: 1372
Merit: 1002


1davout


View Profile WWW
March 12, 2015, 09:28:57 PM
 #2360

The two stage commit doesn't really apply for hard forks however.   With a hard fork you are altering existing rules not just adding new rules.   This means that older nodes will see the new block as invalid.   Not because it has a different version but because it violates an existing rule.  Once the network forks it is committed regardless.  If block 555,555 is 1.1MB then it will never be valid on existing nodes, it doesn't matter if that is the only block on its chain above 1MB and the next million blocks are all smaller because the entire chain is invalid to existing nodes.  As for why 80% vs 75%?   Well I am not sure 80% has been decided in stone, the whole thing is just a proposal at this point.  Maybe Gavin can comment, I would assume he went with a higher threshold since it is the first hard fork.

Yea, I was about to point out that v3 blocks are a soft fork. Thanks for the write up though.


Good to know, can you explain how it will work ?

Deposit one pre-fork BTC, you get credited one post-fork BTC and one gavincoin that you can trade against each other.
Before the fork you withdraw one BTC if you have one post-fork BTC and one gavincoin in your account, after the fork you can withdraw them separately.
If the fork doesn't happen before a certain pre-defined block height all gavincoins in your account are invalidated and you can withdraw post-fork BTC you have in your account as regular BTC.

Pages: « 1 ... 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 [118] 119 120 121 122 123 124 125 126 127 128 129 130 131 »
  Print  
 
Jump to:  

Sponsored by , a Bitcoin-accepting VPN.
Powered by MySQL Powered by PHP Powered by SMF 1.1.19 | SMF © 2006-2009, Simple Machines Valid XHTML 1.0! Valid CSS!