@misc{cryptoeprint:2007:116,
author = {D.R. Stinson and J. Wu},
title = {A Zero-Knowledge Identification and Key Agreement Protocol},
howpublished = {Cryptology ePrint Archive, Report 2007/116},
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.