@misc{cryptoeprint:2013:780,
author = {Nasser Ramazani Darmian},
title = {A Distinguish attack on Rabbit Stream Cipher Based on Multiple Cube Tester},
howpublished = {Cryptology ePrint Archive, Report 2013/780},
year = {2013},
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.