Re: Nothing-at-Stake & Long Range Attack on Proof-of-Stake (Consensus Research)
I just performed this type of attack in APEXcoin. Please see here: https://bitcointalk.org/index.php?topic=897493.0
It was a short-range attack, but the consequences are not just more fees: I successfully double-spent.
You may want to expand this "Short-range attack" category, since there can be many different ways to achieve this.
I did it by splitting the coins and waiting for age to accumulate, and as I mention in the linked thread, I think it may be possible to do something similar in nxt.
Just like with POW, 51% guarrantees success but if you have 10% of the hashrate you will eventually have the chance to double spend. Same thing here: small stake + patience = double-spend. Only worse because in most POS coins the % of actively staked coins is low.
It was a short-range attack, but the consequences are not just more fees: I successfully double-spent.
You may want to expand this "Short-range attack" category, since there can be many different ways to achieve this.
I did it by splitting the coins and waiting for age to accumulate, and as I mention in the linked thread, I think it may be possible to do something similar in nxt.
Just like with POW, 51% guarrantees success but if you have 10% of the hashrate you will eventually have the chance to double spend. Same thing here: small stake + patience = double-spend. Only worse because in most POS coins the % of actively staked coins is low.
Could you describe attack scenario in details? After reproducing it in simulation we would like to pay you pretty good bounty
P.S. Good description on practical impossibility of N@S by JordanLee http://www.peercointalk.org/index.php?topic=2976.msg27303#msg27303