@misc{cryptoeprint:2001:073,
author = {Wen-Guey Tzeng},
title = {Efficient oblivious transfer schemes},
howpublished = {Cryptology ePrint Archive, Report 2001/073},
year = {2001},
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.