@misc{cryptoeprint:2001:037,
author = {Josyula R. Rao and Pankaj Rohatgi},
title = {EMpowering Side-Channel Attacks},
howpublished = {Cryptology ePrint Archive, Report 2001/037},
year = {2001},
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.