Quote from: celkaris on April 14, 2013, 12:37:25 PM

Quote from: crazy_rabbit

TRC has shown that there is an additional computational vector for attack: A difficulty based attack. You can make the chain diff level so high that it slows the rate of production of blocks to the point where the network is at a standstill. Could happen for Bitcoin although you'd need a crazy powerful system to do it.

What would happen with ppc ?

1. i point my popular btc pool to ppc for a while,
2. difficulty starts skyrocketting
3. miners leave

4. repeat 1+2 when needed

how long would it takes to POS to bring difficulty down to a reasonable level back ? Isn't POS efficiency related to the number of running nodes and their coin age ?

This is simply PPCoin's difficulty adjustment algorithm, it's independent of POS afaik... there is nothing stopping TRC from implementing it. PPCoin has shown so far that it's difficulty adjustment algorithm copes very well with ASICs or big increases in mining power. You'll notice a lot of people were telling the TRC devs to incorporate PPC's difficulty adjustment but it fell on deaf ears.

Proof of stake (POS) is what protects against a computational 51% attack.