@misc{cryptoeprint:2010:177,
author = {Robert Granger},
title = {On the Static Diffie-Hellman Problem on Elliptic Curves over Extension Fields},
howpublished = {Cryptology ePrint Archive, Report 2010/177},
year = {2010},
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.