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.
Colmade: Collaborative masking in auditable decryption for BFV-based homomorphic encryption
IH&MMSEC 2022, 10th ACM Workshop on Information Hiding and Multimedia Security, June 27-28, 2022, Santa Barbara, California, USA
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 IH&MMSEC 2022, 10th ACM Workshop on Information Hiding and Multimedia Security, June 27-28, 2022, Santa Barbara, California, USA https://doi.org/10.1145/3531536.3532952
See also:
PERMALINK : https://www.eurecom.fr/publication/6891