@misc{cryptoeprint:2012:249,
author = {Boris Skoric and Jan-Jaap Oosterwijk},
title = {Binary and q-ary Tardos codes, revisited},
howpublished = {Cryptology ePrint Archive, Report 2012/249},
year = {2012},
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.