@misc{cryptoeprint:2011:273,
author = {Kai-Min Chung and Yael Tauman Kalai and Feng-Hao Liu and Ran Raz},
title = {Memory Delegation},
howpublished = {Cryptology ePrint Archive, Report 2011/273},
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.