Template Protection and Renewability for Dynamic Time Warping Based Biometric Signature Verification

Biometric Template Security

The unauthorized copy of the stored biometric data is probably the most dangerous threat regarding users' privacy and security. Therefore, many solutions have been investigated in the recent past to secure biometric templates. Among them, the most promising approaches consist in the implementation of cancelable biometrics [RCB01]. This expression is commonly referred to the application of intentional non-invertible and repeatable modifications to the original biometric templates. Specifically, a properly defined cancelable biometrics should satisfy the following requirements:

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  Security: it should be impossible or computationally unfeasible to obtain the original biometric template from the transformed one;

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  Revocability: it should be possible to revoke a compromised template and issue a new one based on the same biometric data;

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  Diversity: each template generated from a biometrics should not match with others previously generated from the same data;

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  Performance: the recognition performance of the protected system, in terms of False Rejection Rate (FRR) or False Acceptance Rate (FAR), should not degrade significantly with respect to an unprotected system.