@misc{cryptoeprint:2007:257,
author = {Dai-Rui Lin and Chih-I Wang},
title = {A Forward-Secure Signature with Backward-Secure Detection},
howpublished = {Cryptology ePrint Archive, Report 2007/257},
year = {2007},
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.