@misc{cryptoeprint:2004:371,
author = {Vipul Goyal},
title = {Construction and Traversal of Hash Chain with Public Links},
howpublished = {Cryptology ePrint Archive, Report 2004/371},
year = {2004},
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.