Collision resistant encryption scheme

Hi, Is it possible for a secure encryption scheme (I mean IND security)
to have such a plaintext x, that for randomly chosen keys k, k' the
probability that D_k'(E_k(x))=x is non-negligible with respect to the
length of the key? I think that in general it is possible, but I need a
scheme that is resistant to such collisions. Probably there are exist
sufficient conditions that can guarantee that such plaintext does not
exist and the scheme is collision resistant?
Sergei
Received on Tue Feb 7 21:00:05 2006