Cryptology ePrint Archive: Report 2020/122

Verifiable Inner Product Encryption Scheme

Najmeh Soroush and Vincenzo Iovino and Alfredo Rial and Peter B. Roenne and Peter Y. A. Ryan

Abstract: In the standard setting of functional encryption (FE), we assume both the Central Authority (CA) and the encryptors to run their respective algorithms faithfully. Badrinarayanan et al [ASIACRYPT 2016] put forth the concept of verifiable FE, which essentially guarantees that dishonest encryptors and authorities, even when colluding together, are not able to generate ciphertexts and tokens that give inconsistent results. They also provide a compiler turning any perfectly correct FE into a verifiable FE, but do not give efficient constructions.

In this paper we improve on this situation by considering Inner-Product Encryption (IPE), which is a special case of functional encryption and a primitive that has attracted wide interest from both practitioners and researchers in the last decade. Specifically, we construct the first efficient verifiable IPE (VIPE) scheme according to the inner-product functionality of Katz, Sahai, and Waters [EUROCRYPT 2008]. To instantiate the general construction of Badrinarayanan et al, we need to solve several additional challenges. In particular, we construct the first efficient perfectly correct IPE scheme. Our VIPE satisfies unconditional verifiability, whereas its privacy relies on the DLin assumption.

Category / Keywords: public-key cryptography / Inner-product encryption, Verifiability, Functional commitments.

Date: received 5 Feb 2020

Contact author: najmeh soroush at uni lu

Available format(s): PDF | BibTeX Citation

Version: 20200206:144752 (All versions of this report)

Short URL: ia.cr/2020/122


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