@misc{cryptoeprint:2013:532,
author = {Takakazu Satoh},
title = {On a Relation between the Ate Pairing and the Weil Pairing for Supersingular Elliptic Curves},
howpublished = {Cryptology ePrint Archive, Report 2013/532},
year = {2013},
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.