@misc{cryptoeprint:2011:124,
author = {Masao KASAHARA},
title = {A New Class of Biometrics on the Basis of Forgotten Secret Recovering Scheme, KSS(I)},
howpublished = {Cryptology ePrint Archive, Report 2011/124},
year = {2011},
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.