@misc{cryptoeprint:2015:807,
author = {Juan Garay and Björn Tackmann and Vassilis Zikas},
title = {Fair Distributed Computation of Reactive Functions},
howpublished = {Cryptology ePrint Archive, Report 2015/807},
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.