Fundamental Limits for Biometric Identification Systems without Privacy Leakage
Linghui Zhou, Minh Thanh Vu, Tobias J. Oechtering, Mikael Skoglund · 2019
We study the biometric identification systems without privacy leakage. Privacy-preserving biometric identification systems that involve helper data, secret keys and private keys are considered. The helper data are stored in a public database and can be used to support the user identification. The secret key is either stored in an encrypted database or handed to the user, which can be used for authentication. Since the helper data are public and releasing the biometric information invokes privacy issues, the public helper data can only leak a negligible amount of biometric information. To achieve this, we use private keys to mask the helper data such that the public helper data contain as little as possible information about the biometrics. Moreover, a two-stage extension is also studied, where the clustering method is used such that the search complexity in the identification phase can be reduced. identification.