@misc{cryptoeprint:2002:130,
author = {Kazukuni Kobara and Hideki Imai},
title = {OAEP++ : A Very Simple Way to Apply OAEP to Deterministic OW-CPA Primitives},
howpublished = {Cryptology ePrint Archive, Report 2002/130},
year = {2002},
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.