Thus any large escrow service would be a threat to the network, in addition to large miners.
Yes, they can, but technically it will be suicide for them. Anyway, it's possible to prevent such attacks by implementing another REORGANIZE algo.why reorganize? it is still harder and extremally expensive to 51% a PoS blockchain, than a PoW only one.
beauty of PoS concept is that atacker to be succesfuf has to attack himself.
Because clearly, all human creatures are rational (or at least L-rational) and economically motivated.
"man shall not live by bread alone" - said no human, ever
Miners don't have a play in double-spending attack, unless they wait and become stake owner. Security comes from proof-of-stake, proof-of-work only provides minting. Please don't confuse ppcoin's design with other proof-of-stake proposals. Our design is the only one that gives full respect to the concept of proof-of-stake and is the only one that actually has an implementation rather than just talks.
So, basically, this entire ppcoin thing is a bit like Solidcoin sans massive egotism and with less retarded pignode implementation?
Why not discard the PoW component altogether, if it has no "say" in choosing which chain is "goodchain" ?
P.S.:
Disclosure - passerby is affectionately fond of hybrid PoW/PoS things, and hybrid things in general
