@misc{cryptoeprint:2004:044,
author = {Zhou Sujing},
title = {Transitive Signatures Based on Non-adaptive Standard Signatures},
howpublished = {Cryptology ePrint Archive, Report 2004/044},
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.