@misc{cryptoeprint:2012:403,
author = {Juan Manuel Gonz{\'a}lez Nieto and Mark Manulis and Dongdong Sun},
title = {Fully Private Revocable Predicate Encryption},
howpublished = {Cryptology ePrint Archive, Report 2012/403},
year = {2012},
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.