Colmade: Collaborative masking in auditable decryption for BFV-based homomorphic encryption

Ibarrondo, Alberto; Chabanne, Herve; Despiegel, Vincent; Önen, Melek

This paper proposes a novel collaborative decryption protocol for the Brakerski-Fan-Vercauteren (BFV) homomorphic encryption scheme in a multiparty distributed setting, and puts it to use in designing a leakage-resilient biometric identification solution. Allowing the computation of standard homomorphic operations over encrypted data, our protocol reveals only one least significant bit (LSB) of a scalar/vectorized result resorting to a pool of N parties. By employing additively shared masking, our solution preserves the privacy of all the remaining bits in the result as long as one party remains honest. We formalize the protocol, prove it secure in several adversarial models, implement it on top of the open-source library Lattigo and showcase its applicability as part of a biometric access control scenario.


DOI
HAL
Type:
Conference
City:
Santa Barbara
Date:
2022-06-27
Department:
Digital Security
Eurecom Ref:
6891
Copyright:
© ACM, 2022. This is the author's version of the work. It is posted here by permission of ACM for your personal use. Not for redistribution. The definitive version was published in https://doi.org/10.1145/3531536.3532952

PERMALINK : https://www.eurecom.fr/publication/6891