@misc{cryptoeprint:2003:221,
author = {Jung Hee Cheon and Hyun Soo Nam},
title = {A Cryptanalysis of the Original Domingo-Ferrer's Algebraic Privacy Homomophism},
howpublished = {Cryptology ePrint Archive, Report 2003/221},
year = {2003},
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.