CCA-Secure Inner-Product Functional Encryption from Projective Hash Functions

Fabrice Benhamouda (1) , Florian Bourse (2) , Helger Lipmaa (3)

1 IBM Watson Research Center
2 CASCADE - Construction and Analysis of Systems for Confidentiality and Authenticity of Data and Entities
3 University of Tartu

In an inner-product functional encryption scheme, the plaintexts are vectors and the owner of the secret key can delegate the ability to compute weighted sums of the coefficients of the plaintext of any ciphertext. Recently, many inner-product functional encryption schemes were proposed. However, none of the known schemes are secure against chosen ciphertext attacks (IND-FE-CCA). We present a generic construction of IND-FE-CCA inner-product functional encryption from projective hash functions with homomorphic properties. We show concrete instantiations based on the DCR assumption, the DDH assumption, and more generally, any Matrix DDH assumption.

Mots clés: DCR; DDH; inner-product functional encryption; projec- tive hash functions; CCA-security

Domaines: Cryptographie et sécurité [cs.CR]

Fabrice Benhamouda, Florian Bourse, Helger Lipmaa. CCA-Secure Inner-Product Functional Encryption from Projective Hash Functions. PKC 2017 - IACR International Workshop on Public Key Cryptography, Mar 2017, Amsterdam, Netherlands. pp.36-66, ⟨10.1007/978-3-662-54388-7_2⟩. ⟨hal-01613546⟩