Paper 2019/1455

Generic Construction of Server-Aided Revocable Hierarchical Identity-Based Encryption with Decryption Key Exposure Resistance

Yanyan Liu and Yiru Sun

Abstract

In this paper, we extend the notion of server-aided revocable identity-based encryption (SR-IBE) to the hierarchical IBE (HIBE) setting and propose a generic construction of server-aided revocable hierarchical IBE (SR-HIBE) schemes with decryption key exposure resistance (DKER) from any (weak) L-level revocable HIBE scheme without DKER and (L+1)-level HIBE scheme. In order to realize the server-aided revocation mechanism, we use the “double encryption” technique, and this makes our construction has short ciphertext size. Furthermore, when the maximum hierarchical depth is one, we obtain a generic construction of SR-IBE schemes with DKER from any IBE scheme and two-level HIBE scheme.