@misc{cryptoeprint:2011:556,
author = {Yongjia Wang and Xi Xiong and Haining Fan},
title = {GF(2^n) redundant representation using matrix embedding},
howpublished = {Cryptology ePrint Archive, Report 2011/556},
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.