@misc{cryptoeprint:2006:064,
author = {Julien Bringer and Hervé Chabanne and Emmanuelle Dottax},
title = {Perturbing and Protecting a Traceable Block Cipher},
howpublished = {Cryptology ePrint Archive, Report 2006/064},
year = {2006},
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.