Cryptographic protection of biometric templates: Chance, challenges and applications

In this contribution a survey is presented about the possibilities and difficulties of a cryptographic protection of biometric information for the purpose of authentication. The crucial role of sufficient information content of biometric templates will be presented. It will be shown how to use this approach of a cryptographic protection of biometric templates in connection with biometric databases. Finally, a proposal is given, how to combine it with centralised PIN verification procedures in online banking scenarios as a new application scenario. 1. Requirements for the protection of biometric information. Traditional biometric authentication systems store biometric templates together with the data identifying an individual in a database for later comparison. In order to authenticate an individual the biometric data presented is looked up in the database. If a record is found with biometric data that is sufficiently close to that presented, the person is identified. However, the storage of biometric data leads to considerable risks for the authentication system and raises serious concerns regarding data protection. This way of storing biometric data is often criticised as a mass storage of privacy sensitive personal data that is potentially threatened by internal or external attacks on the database. The following risks concerning security and privacy are to be prevented: