Quote from: ddink7 on June 26, 2014, 07:06:31 PM

Quote from: toknormal on June 26, 2014, 06:40:12 PM

Quote from: baddw on June 26, 2014, 05:54:45 PM

This is a fundamental problem with PoS, and is why Peercoin incorporates both PoW and centralized checkpointing. Sunny King is not a stupid guy, he knows that PoS has a big flaw or else he would have implemented pure PoS for Peercoin

I've heard this argument quoted many times.

I don't agree with the idea that there's a "fundamental problem" with POS. I think there are more fundamental problems with POW.

I also think that POS is a far more elegant and modern approach to crypto currencies, being that it more closely represents the idea of "tokenised" wealth than POW does. POW kind of panders to the false premise that a store of wealth has to have "done something to deserve its value". In fact it doesn't and that's a highly flawed analysis of the definition of money in itself.

The fact that you can potentially take control of it by owning more than half the money supply doesn't impress me either as a criticism. In the modern world, you can take control of just about anything by owning more than half of it and as I said before, these are hypothetical scenarios anyway, not practical ones.

So all in all, I see POW as being obsolete. I'm into DRK for other reasons - I don't mind the fact that it's POW - I don't have any problem with that. Bitcoin itself is a POW algo, but if we're comparing "investability" issues based on algo alone, give me POS any day.

Again, the problem isn't that you can take control by owning more than half the money supply. The problem is that the threat of taking control (if credible) is by itself enough to destroy the value of the currency. Creating a credible threat is easier in POS (since it only requires a large amount of money) than it is in POW (since it requires a large amount of scarce hardware to be assembled secretly and come online at exactly the same time).

And actually there are attacks that can be made with good likelihood, with far less than 51% of coins. Owning just 10-20% of coins in some implementations would be enough to commit a double-spend to fool an exchange which depends on a 6 block confirmation, trade for BTC, withdraw BTC and then release the alternate blockchain where the exchange didn't actually receive the coins at all. Rinse, repeat, take all the BTC from the exchange and leave it with nothing.

I do NOT trust Blackcoin, Mintcoin, etc. who basically just copied the PoS algorithm from Peercoin without Peercoin's PoW and checkpointing. These coins WILL be attacked (if they haven't already) and left for dead afterwards. NXT and other coins coded from scratch with fundamentally different PoS implementations could very well be better than Peercoin's descendants.