@misc{cryptoeprint:2007:410,
author = {Daniel J. Bernstein and Tanja Lange},
title = {Inverted Edwards coordinates},
howpublished = {Cryptology ePrint Archive, Report 2007/410},
year = {2007},
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.