リプレイ攻撃や不正なサーバによる攻撃に耐性のある 秘匿生体認証方式

Biometrics authentication is attracting rising attention.Because biological information used in authentication contains a lot of information, it is more difficult to mount impersonation attack than ID/Password scheme. Since biological information contains more critical information, it is necessary to manage biological information securely.To resolve this issue, template protection schemes were proposed, where template protection schemes make it possibleto authenticate users without revealing biological information of template data. Bringer et al. proposed a biometricsauthentication scheme with template protection using error correcting code and homomorphic encryption.The scheme considers the difference between two biometric features as an error, where they are the biometricsinformation in enrollment and authentication process.Furthermore, the scheme uses a XOR homomorphic encryptionto encrypt template data and authenticates users without decrypting their biological information. However, the scheme has two problems. One is nothing that is countermeasure against replay attack, and the other is that selecting parameters is restricted because the scheme uses an error correcting code. In this paper, we propose two schemes that have countermeasures against these problem.One scheme prevents replay attack by adding different values for each session to a query, using DiffieHellman key exchange. The other scheme can set parametersmore flexibility, by using an additive homomorphic encryption without an error correcting code