Yukio Itakura Shigeo Tsujii Proposal on a multifactor biometric authentication method based on cryptosystem keys containing biometric signatures. 288-296 2005 4 Int. J. Inf. Sec. 4 http://dx.doi.org/10.1007/s10207-004-0065-5 db/journals/ijisec/ijisec4.html#ItakuraT05