(Hierarchical) Identity-Based Encryption from Affine Message Authentication

Olivier Blazy (1) , Eike Kiltz (1) , Jiaxin Pan (1)

1 RUB - Ruhr University Bochum = Ruhr-Universität Bochum

We provide a generic transformation from any affine message authentication code (MAC) to an identity-based encryption (IBE) scheme over pairing groups of prime order. If the MAC satisfies a security notion related to unforgeability against chosen-message attacks and, for example, the k-Linear assumption holds, then the resulting IBE scheme is adaptively secure. Our security reduction is tightness preserving, i.e., if the MAC has a tight security reduction so has the IBE scheme. Furthermore , the transformation also extends to hierarchical identity-based encryption (HIBE). We also show how to construct affine MACs with a tight security reduction to standard assumptions. This, among other things, provides the first tightly secure HIBE in the standard model.

Mots clés: IBE; HIBE; standard model; tight reduction

Domaines: Cryptographie et sécurité [cs.CR]

Olivier Blazy, Eike Kiltz, Jiaxin Pan. (Hierarchical) Identity-Based Encryption from Affine Message Authentication. Advances in Cryptology - Proceedings of CRYPTO '14, 2014, Santa Barbara, California, United States. pp.408-426, ⟨10.1007/978-3-662-44371-2_23⟩. ⟨hal-01239920⟩