@misc{cryptoeprint:2005:247,
author = {Charanjit S. Jutla and Anindya C. Patthak},
title = {A Simple and Provably Good Code for SHA Message Expansion},
howpublished = {Cryptology ePrint Archive, Report 2005/247},
year = {2005},
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.