Privacy Implications of Identity References in Biometrics Databases

We analyze the privacy implications of identity references in biometric databases in which either raw biometric samples or templates are stored. The analysis was inspired by the privacy requirement imposed by the Norwegian National DPA (Data Protection Act Privacy Advisor) on the fingerprint data collection for one of our research projects. The respective DPA approved maintenance of a fingerprint database but required deletion of personal information, e.g., name, gender, age, and email address which were collected and stored in a ´namelist´ (XLS-file) as identity references and maintained on a separate hard-disk from the biometric references. We discuss in this paper whether deletion of identity references, as the simplest anonymization way, is appropriate for privacy protection. We take a closer look at the identity attributes and assess to which degree they achieve privacy for an entity based on the proposed criteria. We analyze different biometric database models against the given criteria to give privacy protection guidelines for the identity reference construction and maintenance in a biometric database. In addition, the possibility of joint protection of identity references and biometric references is also investigated in some proposed models suitable for the identity authentication scenario.