@misc{cryptoeprint:2007:046,
author = {Kaoru Kurosawa and Takeshi Koshiba},
title = {Direct Reduction of String (1,2)-OT to Rabin's OT},
howpublished = {Cryptology ePrint Archive, Report 2007/046},
year = {2007},
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.