@misc{cryptoeprint:2009:624,
author = {Jens Bender and Marc Fischlin and Dennis Kuegler},
title = {Security Analysis of the PACE Key-Agreement Protocol},
howpublished = {Cryptology ePrint Archive, Report 2009/624},
year = {2009},
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.