(no title)
verygoodname | 4 years ago
Which part? The fact that storing "length" along with a hash is not superfluous?
You can probably find many things which have a SHA hash of "ca978112ca1bbdcafac231b39a23dc4da786eff8147c4e72b9807785afee48bb" (infinite things, if we assume arbitrary-sized inputs), but you can only find ONE thing which has that hash and has length 1. I just made it impossible (not just unlikely) for you to find a collision.
> The known collision attacks for the MD-family and SHA-1 all in fact produce collisions with the exact same length.
Emphasis mine. And note that I did not claim otherwise in my comment.
tialaramex|4 years ago
The part where you make a false claim out of ignorance.
> You can probably find many things which have a SHA hash of "ca978112ca1bbdcafac231b39a23dc4da786eff8147c4e72b9807785afee48bb"
No reason I should go looking for such things. You're the one making the false claims, if you have found "many things" with that hash then list them to prove your point, otherwise go away.
verygoodname|4 years ago
Which false claim did I make? I'm still waiting...
> No reason I should go looking for such things. You're the one making the false claims, if you have found "many things" with that hash then list them to prove your point, otherwise go away.
You don't need to look for those things. By definition, you know they exist. I don't need to find or enumerate all primes to know that an infinite number of them exist.
For more information, see here: https://en.wikipedia.org/wiki/Pigeonhole_principle
By definition, assuming arbitrarily-sized inputs, there are infinite messages that collide to the same hash value.
But, don't worry... it is clear you have no actual meaningful point to add, so I won't continue this conversation with you any further. Have a nice day.