@misc{cryptoeprint:2011:267,
author = {Myungsun Kim and Hyung Tae Lee and Jung Hee Cheon},
title = {Mutual Private Set Intersection with Linear Complexity},
howpublished = {Cryptology ePrint Archive, Report 2011/267},
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.