Lattice HIBE with Faster Trapdoor Delegation and Applications

摘要

In this paper, we propose a lattice-based HIBE scheme in the standard model with faster trapdoor delegation. It is proven secure under the Learning With Errors assumption. Inspired by Canetti et al.'s transformation (Eurocrypt'03), an HIBE can be converted into a forward-secure public-key encryption (FS-PKE) scheme, and the efficiency of key update relies on the efficiency of trapdoor delegation. For applications, our HIBE with faster delegation can be used to generate a lattice-based FS-PKE with faster key update. Furthermore, we also obtain a lattice-based forward-secure signature (FSS) scheme combining HIBE-like key-update technique with Zhang et al.'s short signature construction in the standard model (Crypto'16).