Quote from: CoinHoarder on November 12, 2014, 07:06:55 PM

Quote from: gatra on November 12, 2014, 05:50:47 PM

Quote from: gatra on November 12, 2014, 05:46:29 PM

Quote from: devphp on November 12, 2014, 05:07:12 PM

Quote from: gatra on November 12, 2014, 04:46:52 PM

Quote from: achimsmile on November 06, 2014, 06:55:42 AM

You just have to buy 51% of the currency or track down majority of stakeholders and compromise their private keys. Much cost free

lots of people seem to believe this (I think it's even mentioned in Sunny King's PPC paper), but it's not accurate: you need 51% of the actively staking coin-age. That's much, much, less than 51% of the currency.
I had some ideas to help fix this, I'm working on it.

Peercoin PoS is not the same as NXT PoS, the latter doesn't use coin-age.

it doesn't matter, it has the same probblem, just replace "coin-age" by "coins".
form their "whitepaper" (actually a wiki):

Quote

tokens must be stationary within an account for 1,440 blocks before they can contribute to the block generation process

this means all coins that are used for transfers cannot be staken and do not count toward the total of which you need 51%
moreover, lots of holders do not stake, so it's not 51% of coins, it's 51% of coins being actively at stake

...and it get worse if you consider NXT has punishments for not staking...

DPoS doesn't suffer from this problem. You would need to buy up 51% of the currency supply to use this attack vector.

Also the Bitshares community believes DPoS is immune to a NaS attack. No one has been able to prove us wrong yet.

More about DPoS: http://bitshares.org/delegated-proof-of-stake/
Even more about DPoS: http://wiki.bitshares.org/index.php/DPOS
Old discussions on DPoS: https://bitsharestalk.org/index.php?topic=4009.0
Discussions regarding "nothing at stake" attacks: https://bitsharestalk.org/index.php?topic=6584.0
More discussion about NaS attack: https://bitsharestalk.org/index.php?topic=6638.0

Great links. I'm heavily supporting DPoS. When organizations, companies and others understand the powerfulness this tool is bringing we will have another little crypto revolution