@misc{cryptoeprint:2010:328,
author = {László Czap and István Vajda},
title = {Signatures for Multi-source Network Coding},
howpublished = {Cryptology ePrint Archive, Report 2010/328},
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.