@misc{cryptoeprint:2008:302,
author = {M. Barbosa, S. Cauchie, T. Brouard and S. Melo de Sousa},
title = {Secure Biometric Authentication With Improved Accuracy},
howpublished = {Cryptology ePrint Archive, Report 2008/302},
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.