| 摘要 |
PROBLEM TO BE SOLVED: To secure safety against an attack on which a malicious server administrator estimates an original feature amount, in cancelable biometric authentication. SOLUTION: In registration, a feature amount array x[i] (i=0 to N-1) obtained by a client 100 is base-converted into an array X[i], converted into a template array T[i]=X[i]K[i]<SP>-1</SP>by use of a conversion filter array K[i], and registered in a server 130. In authentication, a feature amount array y[i] obtained by the client is sorted in reverse order and base-converted into an array Y[i], and then converted into an array V[i]=Y[i]K[i]. The server obtains an array e[i]=Enc(T[i]) by using a homomorphic public-key encryption function Enc, and the client obtains e'[i]=Enc(Σ<SB>j</SB>X[j]Y[j]α<SP>-ij</SP>) from e and V, and shuffles the array for each of the elements. The shuffled array e<SB>σ</SB>'[i] is transmitted to the server and then decrypted to obtain a shuffle correlation array c<SB>σ</SB>[i]. Thus, match/mismatch of the feature amount arrays x, y is determined. COPYRIGHT: (C)2010,JPO&INPIT |
