@misc{cryptoeprint:2011:074,
author = {Daniel J. Bernstein and Tanja Lange and Christiane Peters and Peter Schwabe},
title = {Really fast syndrome-based hashing},
howpublished = {Cryptology ePrint Archive, Report 2011/074},
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.