@misc{cryptoeprint:2006:312,
author = {Iwan M. Duursma and SeungKook Park},
title = {ElGamal type signature schemes for n-dimensional vector spaces},
howpublished = {Cryptology ePrint Archive, Report 2006/312},
year = {2006},
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.