@misc{cryptoeprint:2006:208,
author = {Shuhong Wang and Xuhua Ding and Robert Deng and Feng Bao},
title = {Private Information Retrieval Using Trusted Hardware},
howpublished = {Cryptology ePrint Archive, Report 2006/208},
year = {2006},
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.