@misc{cryptoeprint:2009:165,
author = {Matthieu Rivain},
title = {Securing RSA against Fault Analysis by Double Addition Chain Exponentiation},
howpublished = {Cryptology ePrint Archive, Report 2009/165},
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.