@misc{cryptoeprint:2010:530,
author = {Vanessa Gratzer and David Naccache},
title = {How to Read a Signature?},
howpublished = {Cryptology ePrint Archive, Report 2010/530},
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.