@misc{cryptoeprint:2008:229,
author = {Julien Bringer and Herve Chabanne and Thomas Icart},
title = {Identification and Privacy: Zero-Knowledge is not Enough},
howpublished = {Cryptology ePrint Archive, Report 2008/229},
year = {2008},
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.