@misc{cryptoeprint:2011:117,
author = {Lei Wei and Scott E. Coull and Michael K. Reiter},
title = {Bounded Vector Signatures and their Applications},
howpublished = {Cryptology ePrint Archive, Report 2011/117},
year = {2011},
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.