@misc{cryptoeprint:2014:363,
author = {Mridul Nandi},
title = {Forging Attacks on two Authenticated Encryptions COBRA and POET},
howpublished = {Cryptology ePrint Archive, Report 2014/363},
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.