@misc{cryptoeprint:2001:062,
author = {Jean-Sébastien Coron},
title = {Optimal security proofs for PSS and other signature schemes},
howpublished = {Cryptology ePrint Archive, Report 2001/062},
year = {2001},
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.