ELITE: zEro Links Identity managemenT systEm

Résumé Modern day biometric systems, such as those used by governments to issue biometric-based identity cards, maintain a deterministic link between the identity of the user and her biometric information. However, such a link brings in serious privacy concerns for the individual. Sensitive information about the individual can be retrieved from the database by using her biometric information. Individuals, for reasons of privacy therefore, may not want such a link to be maintained. Deleting the link, on the other hand, is not feasible because the information is used for purposes of identification or issuing of identity cards. In this work, we address this dilemma by hiding the biometrics information, and keeping the association between biometric information and identity probabilistic. We extend traditional Bloom filters to store actual information and propose the SOBER data structure for this purpose. Simultaneously, we address the challenge of verifying an individual under the multitude of traits assumption, so as to guarantee that impersonation is always detected. We discuss real-world impersonation use cases, analyze the privacy limits, and compare our scheme to existing solutions.