@misc{cryptoeprint:2011:467,
author = {M.R.K. Ariffin, M.A. Asbullah and N.A. Abu},
title = {A !ew Efficient Asymmetric Cryptosystem for large data sets},
howpublished = {Cryptology ePrint Archive, Report 2011/467},
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.