@misc{cryptoeprint:2015:857,
author = {Benjamin Fuller and Ariel Hamlin},
title = {Unifying Leakage Classes: Simulatable Leakage and Pseudoentropy},
howpublished = {Cryptology ePrint Archive, Report 2015/857},
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.