@misc{cryptoeprint:2005:146,
author = {Bo Yang, Sambit Mishra, Ramesh Karri},
title = {A High Speed Architecture for Galois/Counter Mode of Operation (GCM)},
howpublished = {Cryptology ePrint Archive, Report 2005/146},
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.