Group Membership Verification with Privacy: Sparse or Dense?

Marzieh Gheisari (1) , Teddy Furon (1) , Laurent Amsaleg (1)

1 LinkMedia - Creating and exploiting explicit links between multimedia fragments

Group membership verification checks if a biometric trait corresponds to one member of a group without revealing the identity of that member. Recent contributions provide privacy for group membership protocols through the joint use of two mechanisms: quantizing templates into discrete embeddings, and aggregating several templates into one group representation. However, this scheme has one drawback: the data structure representing the group has a limited size and cannot recognize noisy query when many templates are aggregated. Moreover, the sparsity of the embeddings seemingly plays a crucial role on the performance verification. This paper proposes a mathematical model for group membership verification allowing to reveal the impact of sparsity on both security, compactness, and verification performances. This models bridges the gap towards a Bloom filter robust to noisy queries. It shows that a dense solution is more competitive unless the queries are almost noiseless.

Mots clés: Group Representation; Verification; Identification; Security; Data Privacy

Domaines: Traitement du signal et de l'image [eess.SP]

Marzieh Gheisari, Teddy Furon, Laurent Amsaleg. Group Membership Verification with Privacy: Sparse or Dense?. WIFS 2019 - IEEE International Workshop on Information Forensics and Security, Dec 2019, Delft, Netherlands. pp.1-6. ⟨hal-02489991v2⟩