12 ms·

> How long until a specified length preimage attack can break bittorrent blocks? Even MD5 still doesn't have a known preimage attack, so... many many years?

• tialaramex 7y ago
  To be fair for MD5 there is a known attack, it's just impractical. It's a real attack though because the whole point of a crypto hash is that you'd have to brute force it to win, and the paper shows a slightly quicker way because MD5 is broken. It's just not quick enough that you could actually do it. Oh wait, perhaps you actually meant preimage as you said rather than I assumed second preimage. OK yes, that isn't ever going to be possible for non-trivial inputs.
  • GoblinSlayer 7y ago
    Cheap talk is hardly an attack though.
  • rocqua 7y ago
    I think OP meant 'viable' pre-image attack. Not just an attack that is better than brute force.