Re: Collision resistant encryption scheme

No, again it is not a homework problem. It is still the same algorithm
which performs the search on encrypted data we discussed some time
before. The algorithm can "find" a wrong string with non-negligible
probability when such collision is possible with non-negligible
probability. I know that there are exists schemes for which such
probability is negligible. E.g. modified IND-CPA secure one-time pad:
E_k(x)=(a, x xor f_k(a)), a - random, f - PRF. I'm just wondering if
there are exist some conditions that can guarantee such collision
resistance (by resistance I mean that the probability of collision is
negligible).
Sergei Evdokimov
Received on Tue Feb 7 21:00:09 2006