I heard that there is nothing at stake with these proof of stake chains.
lol, Actually the ppcoin started trading on
BTC-E.com yesterday, and it has a bit of value. I don't think there are other proof of stake coins, I may have missed something..
I'm a bit of a speculator, I'm thinking ppcoin will blow up and demolish all of the other alt cryptos due to this proof of stake aspect.
Nothing at stake as in when you try double spend bitcoin you have to do it when there are 0 confirmations or waste a lot of money to do 51% or Finney, but for proof of stake you don't loose anything when you try to cheat. Right now PPcoin is some hybrid apparently (details are harder to find than for Bitcoin), but my gut says that when it migrates to pure proof of stake many bad things will happen.
Let me quote one of the devs (with some bolding)
That page is pretty embarrassing. There is absolutely no mention of the fundamental flaw in PoS consensus which none of your proposals have addressed: As of yet none of the proof of stake proposals are workable because there is nothing at stake! If someone is PoS mining it is in their best interest to attempt to concurrently build an honest chain
as well as all possible attack forks just in case one of them happens to win. Under most schemes
this is the profit maximizing move, in all I've seen so far its at least neutral. Mining an attack under PoW actually involves _spending_ something and taking the risk other miners will extend it. PoW works because your work is at stake so even a very small amount of honest miners make mercenary rational miners behave honestly too.
Moreover, I don't see why you argue here that it better aligns incentives. Parties can't mine PoW without having a validating node (or face the extreme risk other miners will toss them off on forks). All it does is redistribute control, which might be useful— if not for the fact that it makes attacking more attractive for selfish participants. I was hopeful of these techniques but as of yet I don't see how any can be workable.