@misc{cryptoeprint:2004:331,
author = {Mihir Bellare and Phillip Rogaway},
title = {Code-Based Game-Playing Proofs and the Security of Triple Encryption},
howpublished = {Cryptology ePrint Archive, Report 2004/331},
year = {2004},
note = {\url{http://eprint.iacr.org/}},
}
You will need the url.sty package (comes with most LaTeX installations) for the last line. Otherwise, remove the \url command.