PPC coin is more secure against 51% attacks, because existing holders of coin don't need large amount of computing power to generate proof-of-stake blocks. To

PPC coin is more secure against 51% attacks, because existing holders of coin don't need large amount of computing power to generate proof-of-stake blocks. To launch a 51% attack against PPC, you need 51% of the computing power and 51% of the coin-age, coins times the amount of time that has past since they were last spent.