| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To secure safety against attack that a malicious server administrator may estimate an original feature value in cancelable biometric authentication. <P>SOLUTION: In authentication, a feature value array y acquired by a client is sorted in reverse order and then base transformation of the reversely sorted feature value array is performed to calculate a base transformation array Y. A mask array r is generated so that a prescribed element is zero and other elements have random values, and the base transformation of the mask array r is performed to calculate a mask filter array R. A server calculates e = Enc(T) by using a homomorphic public-key cipher function Enc and transmits the calculated value to the client together with a public key. The client calculates e' = e^(YK)Enc(R) and transmits the calculated result to the server. The server decodes the e^ to obtain XY + R, calculates a masked mutual correlation function (an expression in the shown figure) by reverse base transformation of the XY + R and determines the coincidence/non-coincidence of a feature value vector from the calculated result. <P>COPYRIGHT: (C)2009,JPO&INPIT</p> |
