@misc{cryptoeprint:2010:163,
author = {Wenping Ma ,Chen Yang and Shaohui Sun},
title = {Golay Complementary Sequences Over the QAM Constellation },
howpublished = {Cryptology ePrint Archive, Report 2010/163},
year = {2010},
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.