@misc{cryptoeprint:1999:005,
author = {Daniele Micciancio },
title = {Lattice Based Cryptography: A Global Improvement },
howpublished = {Cryptology ePrint Archive, Report 1999/005},
year = {1999},
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.