@misc{cryptoeprint:2000:031,
author = {Michel Abdalla and Sara Miner and Chanathip Namprempre},
title = {Forward Security in Threshold Signature Schemes},
howpublished = {Cryptology ePrint Archive, Report 2000/031},
year = {2000},
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.