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1  Bitcoin / Development & Technical Discussion / Re: Proof that Proof of Stake is either extremely vulnerable or totally centralised on: March 04, 2016, 04:58:40 PM
We are interested in trustless, decentralized crypto currency. That is what Satoshi pitched to us in his white paper. Satoshi's design is also flawed though.

Besides this does nothing to stop the attack monsterer outlined. Whose stake is valid? Whose is current, the reorganized block chain or the reorganized one? Which one was the reorganized one? You see proof-of-shit is self-referential and thus can't prove anything about itself.

Trustless decentralized crypto-currency is probably impossible.*  (http://www.links.org/files/decentralised-currencies.pdf)

No matter what the design, in the end you have to trust human beings at some level.  Satoshi's design provided strong incentives for human behavior via costs of physical resources consumption.  The miners have the most skin-in-the-game and can therefore be trusted to behave in the best interests of the system.  The flaw in the design is more apparent than ever right now with the blocksize debate.  Essentially we have non-miners who also have skin-in-the-game in the form of STAKE in the system (e.g. Coinbase, Blockstream, BitPay, users wanting "cheap" transactions, etc.) that are at odds with the incentives of miners.  All want Bitcoin to succeed in different ways, and there is no clear path for miners to decide which is better for them to profit because it is an economic uncertainty that falls outside of the bounds of technical knowledge.

Proof-of-stake consensus gives us a similar situation, but it does so with far less centralization than proof-of-work.  A participant in a proof-of-stake system like Nxt has direct representation and never has their voting rights diluted, and therefore the system can maintain a higher level of decentralization than proof-of-work, where it is inevitable.  Mining today is effectively a barrier-to-entry for anyone who wants to participate in consensus, which is good for some attack vectors (expensive) but bad for others - Bitcoin stakeholders/companies/users have no choice but to lobby centralized miner overlords, which results in social & economic attacks like BitcoinXT/Classic/etc.  If the threat of a fork by a majority of users exists, is there any justification in burning energy?

In my opinion the security trade-offs in proof-of-stake favor decentralization.  The active research in consensus protocols may give us new tools and techniques to sufficiently increase the security of PoS to practical levels of "trustlessness".  The energy efficiency of proof-of-stake consensus as well as the low barrier-to-entry for participants make it a worthwhile pursuit in my opinion, and in the long run Bitcoin itself will benefit from proof-of-stake experimentation.
2  Bitcoin / Development & Technical Discussion / Re: Proof that Proof of Stake is either extremely vulnerable or totally centralised on: March 04, 2016, 12:29:57 AM
max reorg depth in NXT is 720 blocks

Checkpoints are centralization.
Mex reorg depth isn't checkpoints.

It is if you expect it to be honored objectively by offline nodes (propagation isn't objective proof because it can be Sybil attacked). I will let monsterer explain that to you, if you don't understand.

Nodes can identify themselves by cryptographically linking their IP address with an account (called "hallmarking" in Nxt) which mitigates Sybil attacks.  The client can be configured to only download blocks from a subset of nodes linked with known accounts and/or a minimum stake threshold.  In an attack scenario this would allow offline nodes to filter out malicious nodes and sync with the proper chain.  It's basically an optionally enabled reputation layer for trusting nodes linked to known accounts, not a silver bullet because of the flaws with all reputation systems (long term planned exploit) but still helpful as another layer of security.

https://nxtportal.org/peers  ("weight" is the stake of the account linked to the peer)

Example:
https://nxtportal.org/nxt?requestType=getPeer&peer=192.3.196.10

https://nxtportal.org/nxt?requestType=decodeHallmark&hallmark=65758c584d6eba44d405277a76bd58adb7c3f78744300e61ef4d12136539940a0c003139322e332e3139362e313064000000659e33010257b14003389b2904476641824dd076810210aea2f354d5ade07352a8d636f50974a2dd0641d38d5f3ec819f76d8cfd8ed1faff94112dc1269944a91b90267fe4
3  Bitcoin / Development & Technical Discussion / Re: Proof that Proof of Stake is either extremely vulnerable or totally centralised on: March 03, 2016, 03:18:17 AM
To be honest, I'd prefer actual analysis rather than just hyperbole and denial.

I don't think it's at all reasonable to expect all users of a PoS currency to have to understand the inner workings of blockchain consensus. Such a requirement is to require that real everyday people do not use your currency.

Nxt has been running over 2 years and you are now soapboxing the same arguments that have been refuted over and over.  If you think you can easily attack it we have a testnet and plenty of people who would gladly provide you with all the testnet stake you need.  No hyperbole and no harm done, go ahead and prove your claims.  You might want to read the paper that kushti posted first.  The best that you can probably do is a short-range attack that is still impractical.

I expect that you know blockchain consensus is not a purely technical in nature.  Blockchain consensus relies heavily on economic incentives to influence human behavior, whether you are using PoW or PoS.  In the impossible attack you are imagining, many user accounts would cease to exist, which would clearly indicate to any normal user that they are on a fork.  Its no different that imagining that someone secretly breaks SHA256 and mines a new Bitcoin blockchain that outpaces the existing chain.  How do you think people people would react when their bitcoin addresses no longer have any balance?  The chain would be perfectly valid according to the consensus rules.  Would everyone simply shrug their shoulders and accept the loss of all their BTC?
4  Bitcoin / Bitcoin Discussion / Re: Generating Private Keys From Strings Of Words on: July 30, 2015, 02:59:57 AM
Hi.
More people are starting to make their private keys from strings of words. Wallets like MultiBit HD force you to create your private keys from word strings. If Bitcoin grew substantially larger, surely this would present a problem? I could create a program to randomly shuffle words in 24 word strings (the most words MultiBit allows to create a private keys with), to create private keys and check them for a BTC balance on the block chain. If the keys' address had BTC allocated to it, I could simply withdraw it to my own, untraceable wallet.

Is my understanding of Bitcoin correct in this, and if so, surely this could happen if most of the world's population used Bitcoin?

you have to remember that creating a string of random words by a human can not be completely random. so there is a risk of being hacked.

Here's a passphrase generator you can use - https://nxtportal.org/tools/diceware_passphrase.html

Right-click, save-as for offline use.   Smiley
5  Bitcoin / Bitcoin Discussion / Re: A comparison of colored coins on: July 02, 2015, 03:10:39 PM
Just about anything these alt coins think they're bringing to the table can be done with Bitcoin.

Just because it can be done with Bitcoin, doesn't mean it should be, especially if it doesn't fit particularly well.  Bitcoin colored-coins solutions require you to involve a 3rd-party software or sidechain, and different crypto-currencies ARE sidechains, they just use economic "free-market pegs" instead of cryptographic.  

And it has the benefit of the network effect and it's the most secure ledger in the world.

I am looking at Bitcoin solutions. Not alt coins. Every NXT person I have talked to basically wants Bitcoin to fail.

People can be hostile to each other when they have financial interests that they perceive to be threatened.  I certainly want Bitcoin to succeed because it is the value base for other crypto-currencies/DAOs/DACs.  Nxt is an account-based decentralized services platform and you use the tokens (NXT coins) to pay for a variety of transaction types with different fixed fees.  That is nothing like Bitcoin.  Nxt has a lot of digital asset features native in the protocol and you can already do multiple types of deferred & voting based transaction commitments on-blockchain.  If it provides the features you need, at least try it out for free on Nxt testnet.  Nobody is asking you to stop using Bitcoin, and you can always hash your own checkpoints into the Bitcoin blockchain for extra security if you feel guilty.   Wink
6  Bitcoin / Bitcoin Discussion / Re: A comparison of colored coins on: July 01, 2015, 08:12:30 PM
i think you might want to look into NXT.... they have everything you need and its quite under the radar at the moment with active development. they just have a problem marketing themselves...

You forgot to mention that the decentralized voting system allows for asset issuers to create polls where only asset holders can vote based on their balance.  i.e. http://nxtportal.org/polls/1407765120236853374


7  Alternate cryptocurrencies / Mining (Altcoins) / Re: [NEW MINING CLASS] MSCoins - Opportunities for CPU and GPU miners on: January 26, 2015, 01:11:25 AM
I can't mine....

I bought some nxt on Bittrex....but the system says I need 1440 confirmations for my coins....Huh

Is this normal ?

That seems rather excessive.  Try http://shapeshift.io, it doesn't get much faster.


Nd I'm getting this error :

Code:
SEVERE Main.main: Exception during program initialization
.IndexOutOfBoundsException: Index: 0, Size: 0
t java.util.ArrayList.rangeCheck(Unknown Source)
t java.util.ArrayList.get(Unknown Source)
t org.ScripterRon.NxtMint.Main.main(Main.java:296)

Does your NxtMint.conf file have two parameters for the gpuDevice line?

For non-Scrypt hashing (i.e. EGOLD) it should be something like:
gpuDevice=0,256
8  Alternate cryptocurrencies / Mining (Altcoins) / Re: Nxt profitable minting (mining). $26 - some electric cost PER DAY!! on: January 25, 2015, 01:49:44 PM
Another option for a block explorer that has NXT MS currency support -
http://nxtportal.org/search/NXT-GXDT-NMJZ-U96Z-CJ8GJ

Summary view of NXT MS currencies here:
http://nxtportal.org/currencies
9  Bitcoin / Press / Re: [2015-01-04] CD: 19 Crypto 2.0 Projects to Watch in 2015 on: January 05, 2015, 12:11:34 AM
I'm surprised that they completely ignored NXT.  Religious debates aside, that seems pretty biased considering the amount of progress NXT has achieved in one year.  The NXT monetary system is about to go live, which will allow for digital currencies to be be issued and traded on the NXT blockchain, and they can even be minted using proof-of-work or backed by locked NXT.  Following that are plans to implement coin-shuffle on monetary system coins.  IMHO these are going to be very interesting projects to watch in 2015.

https://bitbucket.org/JeanLucPicard/nxt/issue/205/monetary-system-documenation
https://bitbucket.org/JeanLucPicard/nxt/issue/135/coin-shuffling-monetary-system
10  Bitcoin / Development & Technical Discussion / Re: A(nother) downside to Proof-of-Stake? on: November 01, 2014, 01:10:46 PM
Please correct me if I'm wrong, but doesn't PoS require the miners to keep their private keys online on the machine doing block validation?

NXT allows you to lease the balance of your account to another account for forging.  This way you can lease your balance to an empty proxy account that can remain unlocked/online without any risk.  If the account is compromised, you simply issue a new lease transaction for a new account, or move the coins out of the leasing account.  A lease only becomes effective after 1440 blocks to prevent a number of exploits that would otherwise be possible.

http://wiki.nxtcrypto.org/wiki/Nxt_API#Lease_Balance
11  Bitcoin / Press / Re: [2014-09-18] Bitcoin Core Developer Jeff Garzik Believes NXT is a “Scamcoin” on: September 20, 2014, 02:16:33 PM
Tulip mania!  NXT isn't backed by anything, not even mining cartels!

Lots of misinformation here.  NXT is not a clone of Bitcoin, it was written from scratch using java + javascript and has almost nothing in common with Bitcoin aside from the general concept of using a blockchain.

NXT is a platform for decentralized services that is powered by NXT tokens.  Comparing NXT to Bitcoin as a "currency" doesn't really make any sense.  NXT and Bitcoin can function as complimentary systems (they already do) as NXT was designed from the ground-up to process a variety of transaction types that are not suitable for the Bitcoin blockchain.  I like NXT because I like being involved in projects with promising technology and contributing effort to help them grow - the same reasons I got into Bitcoin.  If a fatal flaw is discovered in the NXT PoS mechanism it will probably fail, but we won't know with any certainty unless we try.  Nobody is forcing anyone else to use NXT and it's certainly not a "scam".



Quote from: CoinMode
tl;dr If it isn't a mine-able crypto, then it isn't good

If you want to "mine" NXT, you can use a pool like http://hashrate.org.  It mines other alt-coins and automatically sells them to buy NXT that it pays out to miners.   Smiley
12  Bitcoin / Meetups / Re: Enthusiasts in Pittsburgh, PA? on: July 15, 2014, 08:07:04 PM
http://www.meetup.com/Pittsburgh-Bitcoin-Users/
13  Economy / Service Discussion / Re: Can I call the blockchain.info API with just javascript or jQuery? on: May 30, 2014, 03:18:19 PM
You need to use an ampersand for query parameters: "&cors=true"

ex -
Code:
$.getJSON("http://blockchain.info/unspent?active=1CjPR7Z5ZSyWk6WtXvSFgkptmpoi4UM9BC&cors=true", function (data) { alert(JSON.stringify(data)); });
14  Alternate cryptocurrencies / Altcoin Discussion / Re: Bitcoin, Litecoin,... What's next? on: March 19, 2014, 08:27:47 PM
NXT decentralized services.

15  Economy / Goods / Re: [For Sale] Bitcoin Accepted Here : Neon Signs - Now Shipping! on: March 11, 2014, 12:42:39 AM


Arrived today, safe and sound with the excellent packaging.  Thanks again!   Smiley

16  Alternate cryptocurrencies / Announcements (Altcoins) / Re: NXT :: descendant of Bitcoin - Updated Information on: March 10, 2014, 04:21:39 PM
Is DoS expected to be more of a problem with TF than regular forging?   If we can guess who will forge the next block with a high degree of probability, won't an attacker do the same?

If this was already discussed, can someone point me to it?  I'd like to find more detailed information on how TF is planned to be implemented.


edit -
Just noticed this is mentioned in the faq, but not really answered fully.

http://www.thenxtwiki.org/wiki/FAQ - "This is possible. If it is a concern for you, you should run your Nxt software through a personal VPN service or Tor. "

17  Bitcoin / Mining software (miners) / Re: CGMINER ASIC miner monitoring RPC linux/win/osx/mips/arm/r-pi 4.0.1 on: March 07, 2014, 10:24:54 PM
For sure that will reduce overall cpu usage with 20-30% that is what i observe on my tplinks


That fixed it, thanks.  After disabling LOCK_TRACKING 4.0.1 is now running at a very steady 11% on my system, which is actually a nice improvement over 3.9.   Smiley
18  Bitcoin / Mining software (miners) / Re: CGMINER ASIC miner monitoring RPC linux/win/osx/mips/arm/r-pi 4.0.1 on: March 07, 2014, 02:55:40 AM
EDIT: Also, cpu usage by cgminer seems to have greatly increased. I noticed these things with two machines running Windows 7.

I wanted to post the same observation.  I've been upgrading every few releases and had been on 3.8-3.9 for a long time with a few BFL units.  In 3.9 the CPU usually averages around 15%-16%.  Going to 4.0.1 the CPU usage slowly increases and levels off at ~35%.

Ubuntu 12.04.4 x64, 3.11 kernel, gcc 4.6.3
CFLAGS="-O2 -Wall -march=native" ./configure --enable-bflsc

19  Economy / Service Announcements / Re: BitcoinWisdom.com - Live Bitcoin/LiteCoin Charts on: February 18, 2014, 01:53:01 PM

Can't find the NXT donation address in your sig...   Grin
20  Alternate cryptocurrencies / Altcoin Discussion / Re: Transparent mining 2, or What part of Legacy should be left behind on: February 10, 2014, 06:52:57 PM
Owning NXT is somewhat like owning shares in a virtual public company.  The shares were issued all at once, but they happen to be coins that are traded on crypto markets, which is nice because they are accessible to anyone.  They function as both shares and as the resource used in the network itself.

The forging fees are not attractive right now as an incentive for profit because there is no real activity yet.  To me, forging fees are more of a programmatic "dividend" that is built into the shares.  You are only paid this dividend if you show up to shareholder meetings (run a client with an unlocked account)(run a node).
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