@misc{cryptoeprint:2014:211,
author = {Subhabrata Samajder and Palash Sarkar},
title = {Some Randomness Experiments on TRIVIUM},
howpublished = {Cryptology ePrint Archive, Report 2014/211},
year = {2014},
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.