@misc{cryptoeprint:2009:551,
author = {Hongbo Zou},
title = {A Novel Design Method of Stream Ciphers Based on Table-Element Permutation},
howpublished = {Cryptology ePrint Archive, Report 2009/551},
year = {2009},
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.