@misc{cryptoeprint:2010:138,
author = {Manoj Kumar},
title = {On the Security of a Novel Remote User Authentication Scheme using Smart Card based on ECDLP},
howpublished = {Cryptology ePrint Archive, Report 2010/138},
year = {2010},
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.