@misc{cryptoeprint:2005:367,
author = {Dong Jin Park, Juyoung Cha, and Pil Joong Lee},
title = {Searchable Keyword-Based Encryption},
howpublished = {Cryptology ePrint Archive, Report 2005/367},
year = {2005},
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.