@misc{cryptoeprint:2000:032,
author = {Birgit Pfitzmann, Ahmad-Reza Sadeghi},
title = {Anonymous Fingerprinting with Direct Non-Repudiation},
howpublished = {Cryptology ePrint Archive, Report 2000/032},
year = {2000},
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.