@misc{cryptoeprint:2010:508,
author = {Jose Carrijo and Rafael Tonicelli and Anderson C. A. Nascimento},
title = {A Fault Analytic Method against HB+},
howpublished = {Cryptology ePrint Archive, Report 2010/508},
year = {2010},
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.