@misc{cryptoeprint:2005:027,
author = {Masayuki ABE and Rosario Gennaro and Kaoru Kurosawa},
title = {Tag-KEM/DEM: A New Framework for Hybrid Encryption},
howpublished = {Cryptology ePrint Archive, Report 2005/027},
year = {2005},
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.