@misc{cryptoeprint:2015:839,
author = {David Wong},
title = {Timing and Lattice Attacks on a Remote ECDSA OpenSSL Server: How Practical Are They Really?},
howpublished = {Cryptology ePrint Archive, Report 2015/839},
year = {2015},
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.