Cryptology ePrint Archive: Report 2018/563

Multi-client Predicate-only Encryption for Conjunctive Equality Tests

Tim van de Kamp and Andreas Peter and Maarten H. Everts and Willem Jonker

Abstract: We propose the first multi-client predicate-only encryption scheme capable of efficiently testing the equality of two encrypted vectors. Our construction can be used for the privacy-preserving monitoring of relations among multiple clients. Since both the clients’ data and the predicates are encrypted, our system is suitable for situations in which this information is considered sensitive. We prove our construction plaintext and predicate private in the generic bilinear group model using random oracles, and secure under chosen-plaintext attack with unbounded corruptions under the symmetric external Diffie-Hellman assumption. Additionally, we provide a proof-of-concept implementation that is capable of evaluating one thousand predicates defined over the inputs of ten clients in less than a minute on commodity hardware.

Category / Keywords: multi-client functional encryption, predicate-only encryption, privacy-preserving multi-client monitoring

Original Publication (with major differences): CANS 2017

Date: received 4 Jun 2018

Contact author: a peter at utwente nl

Available format(s): PDF | BibTeX Citation

Version: 20180604:225333 (All versions of this report)

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