Quote from: camosoul on June 09, 2014, 11:44:45 PM

Quote from: AlexGR on June 09, 2014, 11:41:14 PM

I was updating the list of anonymous (promised to be) coins and was skimming through posts in the dreamcoin thread... at some point I read this by the dreamcoin dev:

https://bitcointalk.org/index.php?topic=599854.msg6840209#msg6840209

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I really think a lot of you people need to bring it down a notch, aimless threats are not going to help...

I said I would leave if I keep getting threats, the threats better stop. #1 I created Dreamcoin, it is still a solid all around good PoS coin (Better than Blackcoin). #2 - Zerocoin integration is huge, yes everyone wants it, yes everyone wants it now, but same with the iPhone 6 and Darkcoin's DarkSend source, etc. Sometimes things take time, give it time guys, with actual community support, that would be ideal, not trolling me and my personal life and then freaking out if I don't post back within 24 hours....

Needless to say, I lol'ed Cheesy

Solid PoS.... Petrified poop?

How can Proof of Stake ever result in "a solid coin?"

Isn't there enough stupid in here already?

Not everyone knows about the "nothing at stake" attack.

If anyone wants to read about it: https://bitcointalk.org/index.php?topic=615843.msg6751334#msg6751334

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Quote from: DeathAndTaxes on May 15, 2014, 08:42:49 PM

Quote from: ChuckOne on May 15, 2014, 08:32:07 PM

Quote from: grau on April 24, 2014, 11:42:50 AM

This is a problem at any stake. Random coalitions to alter the past can be formed at no cost to those colluding.
Checkpointing is not an alternative to decentralized consensus but central override of it.

The same works for Bitcoin, too.

You misunderstand. The risk isn't that someone could attack the network, it is that they could attack the network with no cost.

Imagine bitcoin worked using a PoS. An early adopter had acquired 1M BTC at one time in the past but over time he lost/sold/spent/transferred them. Today he has no bitcoins but the blockchain contains a history of a time when he did have 1M BTC. If the amount of the stake being used is <1M BTC he could rewrite history not by using coins he has today (a real cost), not by buying millions of mining rigs (a real cost) but by using the history of the coins he once had (no cost). He has absolutely nothing at risk and nothing to lose. If he and potentially others decided to attack the network they would rewrite the blockchain starting from when they had a larger stake, creating a parallel history where they didn't lose/sell/spend/transfer the coins.

They can attack the network based on what they had (but no longer do) in the past. There is nothing at risk and no cost to the attack. THAT is the PoS problem.

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If bitcoin miners collude, they could alter the past.

Sure they can, however there is a cost to that attack and there is something at risk which they lose if they fail. With PoS you can attack the network for "free" using something you had but no longer do. It is very hard to secure against an attack where the attacker can do so at any time without any cost and without any risk.