....
That is is you want to have a guaranteed successful 51% attack...than 51% of the total coins STAKING....
barabbas you know that there are systems like PPC NOVA are using to prevent small amounts to make 51% attack
they are preventing it because of stake modyficators time stamps many other combined solutions that only core coders understand not you...
At the end you have centralized CHECKPOINTs and no 51% attack is possible because of that...
POS system is not like just that you have 51%of stake and you will attack...
look how Nova is preventing 51% attack with having only 25% coins those technologies are known...
in fact when you have centralized checkpoint you are safe from 2x spend
cause checkpoint servers will chose right chain for you...Stop telling how you know POS while you are far away from tech aspects of case.
I am noob too but i know "a little more".
Tech info below ( BC in POS 2.0 pushed even further those security ... )
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http://coinwiki.info/en/NovacoinStake generation issues
The main proof-of-stake design problem is that unlike proof-of-work hashing rate, stake weight could be used multiple times without any overhead. It allows potential attacker to repeat his attempts to generate consecutive stakes until he will get lucky enough. And there is high probability to success without holding large stake,
20–25% of total weight (not coins) will be more than enough. Attacker can retry his attempts to generate consecutive stakes 1,000, 50,000, or 1 million times without any problem, using the same outputs.[12][13]
This could be worked around using centralized check-pointing. Novacoin creators resolved this issue using balanced weighting scheme.[14]
Centralized check pointing
As PPCoin ideas descendant, Novacoin is not truly a decentralized currency as it still requires centralized check pointing to avoid several issues.[15] The Novacoin developer has announced however that this check pointing is only a temporary measure which will be removed once the currency grows sufficiently stable. The centralized checkpoints feature could be disabled manually using -nosynccheckpoints option for official client.