I'd be sad..  |
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I find your criticism valid and it applies to all forms of POS that I know of. However I don't see it as problematic, as long as you have a way to get that "external 'number'" in a secure/trusted/decentralized enough way.
Thanks gatra. That about covers my worries for long range attacks. Thinking about the internal chain consensus rules, maybe a different approach might produce some new ideas. It seems the 'issue' is that a rational miner will try to mine multiple chains, not just because he can, but more importantly because he might make more money that way. Why not remove that incentive altogether instead of punishing/blacklisting him for trying. Currently in Pure POS systems, the miners still 'compete' for who gets to mint the next block. Whoever does, gets the spoils. Thereby incentivising multiple chain mining. I know TF in NXT picks a miner, but that does not stop miners trying to extend earlier chains in history to find a different TF path through the miners. If you see what I mean.. What if you say anyone can mint the next block, and then pay EVERYONE, EVERY block. Therefore every chain pays the same. Therefore there is no incentive to mine multiple chains. You could use a 'Hash Clock' to pick a miner at random every 10 seconds or so (Like POW but more hashing power has no effect), and then you would calculate the value BLOCK FEES / TOTAL COINS. This would give you a tiny percentage that you could multiply ALL ACCOUNT balances by to spread the fees proportionally to everyone.. So if the block fees were 1 unit, and the coin had 100 coins in all, every account would increase by 1/100, 1%. This would mean that you would not need to actually run a node to be paid, BUT, if you were a large stakeholder and wanted your investment to be secured, why wouldn't you run a node ? I can see that there are issues with the idea, why anyone would run a node, as there would be no gain financially from doing so. The network would not run if enough miners did not choose to run a node. So I wonder - would stake holders choose to run a node - for the good/health of the network ? |
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i can always / later verifiably proove that this POW chain is better than that one. By summing the work.
What makes you think the same isn't true in some POS implementations Which POS are you criticising, an actual one or a straw man you invented? Pure POS. I'm not trying to debunk POS. I really like certain aspects of it. Just some points, as with POW, still seem unfinished \ problematic. This thread is about pure POS N@S resistance, and I have not seen an answer to that yet. Anywhere.. Can you refer me to \ explain a version of POS which can compare valid chains without any external 'number' to bootstrap the process? (I'm not talking short range attacks, but long-range-total-chain rewrites) Thanks. |
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If a Trojan horse in the github repo is the source of the attack vulnerability, then bitcoin is just as vulnerable.
No, it is not. As I said - the VALID POW chain can still be determined without any outside assistance. Once you have hacked the repo - i can always / later verifiably proove that this POW chain is better than that one. By summing the work. You can't with POS. |
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Vitalik has moved the goal posts..
We know you cannot get the same level of 'independent verifiablilty' from POS chains as POW, but he's saying 'Does that matter ?'
Valid point.
POS systems need a 'number' to initialise. That's it.
If you're happy with that, POS away.
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Trust.
BUT - he is saying that's no problem.
I disagree.
Do you have any reason for disagreeing, or just stubbornness? In my paper on the Decrits consensus algorithm, I called it common sense, because that's exactly what it is -- not trust. In bitcoin, in lieu of common sense, you have an algorithm that will idiotically allow anyone with enough hash power to commit fraud against you. To reduce the likelihood of this fraud, hundreds of millions and what will eventually be billions of dollars of wasted electricity and capital must be spent annually to make it more difficult. In stake algorithms, you have virtually no cost to protect against this, you must only rely on the user to be modestly aware of what millions or billions of other people who were watching the network think is the correct chain of events, and this is only if you specifically are being targeted for fraud. And how are you being targeted if you aren't even watching the network? And with the DCA I even solved the problem so that you don't have to even use common sense if you haven't monitored the network recently -- except if a massive, one-time attack has occurred in the mean time. And again, it only matters if you were being targeted. Unlikely that you would part with a massive amount of goods without monitoring the network, though. Etlase2! (That is you ?) hello..  Love that you're still plugging Decrits. As for this POS/POW conundrum, I am realising that this is a psychological/philosophical argument. Mathematically some people will not be swayed - on both sides  POS systems need a startup value to initialise (basically). That's fine. But where this 'number' comes from, always troubles me. Average Joe User will not be anywhere near it. His software client will deal with it, and that will come from some github repo that someone else has compiled. Probably the same main repo most people use. That is the weak link and where the eventual attack will come IMHO. And that's about it. However you wrap it up, some of us find that discomforting just as some find POW untenable. You cannot hack a POW chain in this way. The chain itself is INDEPENDENT of the software, unlike POS systems. POW chains can be compared to another POW chain on it's own merits/work. I'm thinking that eventually the attack on POS will come from a large POW stake holder. Sort of like currency wars. One coin attacking another. Sounds exciting. |
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Err.. So Vitalik agrees.
'.the solution is simple: the first time they sign up, and every time they stay offline for a very very long time, they need only get a recent block hash from a friend, a blockchain explorer, or simply their software provider, and paste it into their blockchain client as a “checkpoint”. '
Trust.
BUT - he is saying that's no problem.
I disagree.
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No, I don't use the old addresses. No extra coins.
They're new users. Don't have to convince them.
I do give most old users their balance back though so they don't mind which chain.
Keep the rest..
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What if I created my own genesis block, with new accounts I have access to?
And a small botnet loyal to me. Playing along with the network.
How would a new user know my chain vs the original?
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hmm.. A lot of POS talk lately. It is a nice garden to play thought experiments in, I'll admit.. If I write my own POS chain, from the genesis block, in secret, I can make sure that my chain doesn't have any/many double signatures ? I can make it anything I like.. and obviously wouldn't release it until it had a greater 'V(u)' than the current valid chain. The only way I know of choosing the 'valid' chain, if you can call it that, is by centralised checkpoints.. As for a punitive scheme, check out Slasher by Vitalik.. https://blog.ethereum.org/2014/10/03/slasher-ghost-developments-proof-stake/ |
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Well - in a POW chain, you see which chain has the most WORK put into it. This is independent of anyone. You just sum it up and choose the one with the most.
Well - in a POS chain, you see which chain has the most STAKE put into it. This is independent of anyone. You just sum it up and choose the one with the most. simple as that. I'm sorry - It's not. My INVALID chain has just as much stake put into it as the VALID one. I bought accounts that are empty now but were full of coins sometime in the past.. (Or hacked an exchange to get the keys to their now empty wallets etc..) then my node would ignore your chain because it's invalid. Of course.. But since I now have bots running half the network, any NEW user would download MY CHAIN. And here's the kicker, they would have NO (trustless) WAY of knowing which of us is pushing the VALID chain. As for Economic Clustering.. Just 'Trust' wrapped up in a more complex way.. |
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Well - in a POW chain, you see which chain has the most WORK put into it. This is independent of anyone. You just sum it up and choose the one with the most.
Well - in a POS chain, you see which chain has the most STAKE put into it. This is independent of anyone. You just sum it up and choose the one with the most. simple as that. I'm sorry - It's not. My INVALID chain has just as much stake put into it as the VALID one. I bought accounts that are empty now but were full of coins sometime in the past.. (Or hacked an exchange to get the keys to their now empty wallets etc..) |
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Let's try a different attack..
When you first connect to a POS network you need to download the current valid chain.
If 2 Chains are presented to you what happens ?
Well - in a POW chain, you see which chain has the most WORK put into it. This is independent of anyone. You just sum it up and choose the one with the most.
In a POS chain, there is no way of knowing which chain is MORE valid than the other. You need to TRUST someone.
If I run a bot-net, that behaves absolutely correctly, so that it takes up 'Half' of the valid nodes in a network (EASY - even bitcoin is only 7000 nodes), for months, I can then launch a nice attack.
My assumption is that either I HAD - years/months/days back - an account with a large stake in the POS network but now do not or I buy the key off someone who had a large balance in the past - maybe from one of the 77 initial NXT stake holders.
I push out a chain, that I generate from way back when (Splitting it up etc etc to mask the hack), where everyone has the same balance (So you won't mind) EXCEPT for 2 or 3 large accounts where all the money has been given to me.
My bot net accepts it as valid and pushes it out as the correct chain.
The solution, for normal users, is to check with HEAD OFFICE - say the main NXT nodes - which is the valid chain, sure, but this requires something distributed consensus is supposed to remove. Trust.
Again - I like POS - it's just not ready for primetime yet, and worse, we still have no idea it ever will be.. (trustless)
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I really like POS. I do. But there's an issue.. I won't go into the details, we all know what they are, but to break it down to it's simplest : POS needs 1, just 1, TRUSTED number to start with, when you log in to the network. Then it's good to go (BASICALLY). However the POS coins wrap it up, NXT, blackcoin, DPOS systems etc etc. That's the bottom line. Whatever ANYONE SAYS. If you can handle that fact and don't mind, go for POS. POW has flaws, yes, BUT there is no TRUST required at any stage. If this matters to you, POW is the only way to go. For the most complete breakdown of the issues : https://blog.ethereum.org/2014/07/05/stake/and then https://blog.ethereum.org/2014/10/03/slasher-ghost-developments-proof-stake/ |
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'Neptunes Brood' !
Nice. Hard. Sci. Fi.
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I'm sorry you lost coins. That's never a pleasant feeling.. Can I ask the OP what computer he has ? Windows, Mac or Linux ? And did you ever access your blockchain.info account from an internet cafe ? |
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I work on UK time, so gonna bump this for our US friends..
Just wanted to mention the coins that we currently support.
Litecoin, Feathercoin, Megacoin, Maxcoin, Auroracoin, Dogecoin, Novacoin, Zetacoin, Vertcoin, Blackcoin, DarkCoin and obviously Bitcoin..
If you would like another coin added, let us know!!
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WWW.LBCSE.COM - London Bit Coin Secure Exchange Hello Fellow Crypto-Coiners! It is my great pleasure to announce a new Alt-Coin exchange I am working on. It is still in semi-BETA (Everything works and last bug was a week ago), so would love some feedback. To make things easier, we give you a FREE Coin Pack of ALL the coins we currently support just for signing up (IF you use a referrer), so you can test it for free immediately Use my link to start trading right away : https://www.lbcse.com/public/freecoins.php?ref=VTEMWRWe have a VERY generous referral program, and will give you up to 40% of the commissions from users you bring to the site. So, should you wish to post about us on another forum, Reddit, FaceBook etc etc.. be sure to use YOUR OWN referral link. (In your Account section) Obviously, I have tried to make the best exchange possible, and we have some UNIQUE features which I think you will like. 1) Publicly auditable coin addresses, where all the various coins are stored, so you can verify that we have what we say we have. You can see this at https://www.lbcse.com/support/siteinfo.php 2) Fully load-balanced HTML servers with SQL cluster backend. 3) Secure OFFLINE cold wallet, for the bulk of coins, with smaller ONLINE hot wallet for fast withdrawals of small amounts. Again, all fully auditable. 4) We have an original and powerful interface. 5) TFA (2 Factor Authentication) for complete security. 6) VERY low commissions. 0.1% for market makers, 0.2% for market takers. 7) Full API to interface with the site. And more.. If you find a BUG, please let me know, as well as any other comments or criticisms you may have. Useless abuse, not so much..  Thanks. Enjoy.
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Hello, I would like to advertise on your excellent site ? I'm working on a new Crypto Exchange - www.lbcse.com - which has some nice features, like full online Coin Balance checking via 3rd Party.. :-) We have a very generous referral program that pays 40% of the commissions to the referrer, but we are also fully open to just paying you directly. Is this something that you think we can discuss further - and if so please pm me. Thanks! |
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Hi,
I am trying to run the worldcoind daemon but I get constant connection timeouts when trying to connect to the network ?
I have seen that this is a known bug ?
To do with the peers.dat file.
Is there a fix ?
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