@misc{cryptoeprint:2004:132,
author = {R. Granger and D. Page and M. Stam},
title = {On Small Characteristic Algebraic Tori in Pairing-Based Cryptography},
howpublished = {Cryptology ePrint Archive, Report 2004/132},
year = {2004},
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.