[quote=“mhps, post:24, topic:2518”][quote=“josojo, post:17, topic:2518”]Clock drift problem:
Smike elaborated how this works in http://www.peercointalk.org/index.php?topic=2634.0.
He states:
[…]
I am not sure, but I think that if an attacker attacks the network over 1 hour - assuming he wants to reorganize 6 blocks - then he can try 14400+7200 timestamps instead of just 7200 timestamps. For sure this would be an advantage for the attacker, but still he has to have many many coins…[/quote]
I think the problem is still there, although not as severe. For every new block there would be 7800 (2hr+10min) tries than 600 (10min).[/quote]
Ups I messed up with the numbers, but the way I calculated things were right!
Right version:
If an attacker attacks the network over 1 hour - assuming he wants to reorganize 6 blocks - then he can try 7200+3600 timestamps instead of just 3600 timestamps.
mhps, your calculation is wrong, since the hash of a new block is not part of the hash the minter calculates in order to find a new block. Probably, you have not seen sigmike last post in the thread mentioned above:
Is it right? In the (N+1)th second the difficulty and the hash for the previous block have all changed so you won’t get the same hash with timesptamp=N as you did in the Nth second (when timesptamp was N). All 14400 hashes would be new compared with the last second.[/quote]
Actually the previous block hash in not part of the hash you compute in PoS. So the 14400 hashes stay the same even if there’s a new block.
The only thing that may change is the difficulty.[/quote]