@misc{cryptoeprint:2008:386,
author = {Michael Lifliand},
title = {Shared Key Encryption by the State Machine with Two-Dimensional Random Look-up Table},
howpublished = {Cryptology ePrint Archive, Report 2008/386},
year = {2008},
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.