## CryptoDB

### Paper: Multi-Input Functional Encryption for Inner Products: Function-Hiding Realizations and Constructions Without Pairings

Authors: Michel Abdalla Dario Catalano Dario Fiore Romain Gay Bogdan Ursu DOI: 10.1007/978-3-319-96884-1_20 (login may be required) Search ePrint Search Google Slides CRYPTO 2018 We present new constructions of multi-input functional encryption (MIFE) schemes for the inner-product functionality that improve the state of the art solution of Abdalla et al. (Eurocrypt 2017) in two main directions.First, we put forward a novel methodology to convert single-input functional encryption for inner products into multi-input schemes for the same functionality. Our transformation is surprisingly simple, general and efficient. In particular, it does not require pairings and it can be instantiated with all known single-input schemes. This leads to two main advances. First, we enlarge the set of assumptions this primitive can be based on, notably, obtaining new MIFEs for inner products from plain DDH, LWE, and Decisional Composite Residuosity. Second, we obtain the first MIFE schemes from standard assumptions where decryption works efficiently even for messages of super-polynomial size.Our second main contribution is the first function-hiding MIFE scheme for inner products based on standard assumptions. To this end, we show how to extend the original, pairing-based, MIFE by Abdalla et al. in order to make it function hiding, thus obtaining a function-hiding MIFE from the MDDH assumption.
##### BibTeX
@inproceedings{crypto-2018-28853,
title={Multi-Input Functional Encryption for Inner Products: Function-Hiding Realizations and Constructions Without Pairings},
booktitle={Advances in Cryptology – CRYPTO 2018},
series={Lecture Notes in Computer Science},
publisher={Springer},
volume={10991},
pages={597-627},
doi={10.1007/978-3-319-96884-1_20},
author={Michel Abdalla and Dario Catalano and Dario Fiore and Romain Gay and Bogdan Ursu},
year=2018
}