@misc{cryptoeprint:2014:729,
author = {Daniel J. Bernstein and Tung Chou},
title = {Faster Binary-Field Multiplication and Faster Binary-Field MACs},
howpublished = {Cryptology ePrint Archive, Report 2014/729},
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.