@misc{cryptoeprint:2011:435,
author = {Yehuda Lindell and Benny Pinkas and Eli Oxman},
title = {The IPS Compiler: Optimizations, Variants and Concrete Efficiency},
howpublished = {Cryptology ePrint Archive, Report 2011/435},
year = {2011},
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.