Quote from: WilliamLie2 on June 06, 2014, 08:02:14 PM

Quote from: DeepCryptoanalist3 on June 06, 2014, 07:58:54 PM

Quote from: WilliamLie2 on June 06, 2014, 07:52:01 PM

Quote from: HunterMinerCrafter on June 06, 2014, 07:44:05 PM

I'm still not convinced that this is meaningfully exploitable. Anyone care to demonstrate? Cool

How fast your bot can mine new blocks? Can it generate one block at least every few seconds? If so, just start to generate blocks right from the genesis block untill you will have more blocks then there are currently, then send all your newly mined blocks to the network, voila, and you will own all of motocoins except for my premine. This is just a 51% attack.

No it is not a 51% attack because it is not involve much resources to accomplish. Because in motocoin threshold value is not linked to block issue time attacker can produce blocks whose solution is stupid and slow.

It is like producing a blockchain for bitcoin where eachblock have only one leading zero. This is not a 51% attack by definition because attacker can have far less resources than the rest of the net. He only shall be able to make form blocks fast enough.

I'm just saying that current network difficulty is too low and you don't actually need to use this vulnerability to perform attack.

I still don't really see how this is any different from a 51% against any coin. On any coin if one dominates hashing power (by some multiples) they can rewrite block history - including difficulty. If you had sufficient hashing power you could produce a btc chain with a different final difficulty as well. (Probably not as low as 1 bit, but certainly lower than the current difficulty.) It would just have to be a longer chain and end with a block holding a timestamp close enough to the wall clock. What am I missing here?

EDIT: Wait, maybe I do see what you mean after all... basically "median" is both not actual median, and also ultimately has no impact on the retarget if target==actual. (Or is very very close.) Am I on the right track now?