@misc{cryptoeprint:2011:297,
author = {Igor Semaev and Mehdi M. Hassanzadeh},
title = {NEW STATISTICAL BOX-TEST AND ITS POWER},
howpublished = {Cryptology ePrint Archive, Report 2011/297},
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.