Anonymous HIBE with Short Ciphertexts: Full Security in Prime Order Groups

TL;DR

This paper introduces the first efficient anonymous HIBE scheme with short ciphertexts in prime order bilinear groups, achieving full security in the standard model and demonstrating practical performance improvements.

Contribution

It presents a novel anonymous HIBE scheme with short ciphertexts in prime order groups, fully secure under standard assumptions, and provides implementation benchmarks.

Findings

Scheme achieves full security in the standard model.

Ciphertexts are shorter compared to previous schemes.

Implementation results demonstrate practical efficiency.

Abstract

Anonymous Hierarchical Identity-Based Encryption (HIBE) is an extension of Identity-Based Encryption (IBE), and it provides not only a message hiding property but also an identity hiding property. Anonymous HIBE schemes can be applicable to anonymous communication systems and public key encryption systems with keyword searching. However, previous anonymous HIBE schemes have some disadvantages that the security was proven in the weaker model, the size of ciphertexts is not short, or the construction was based on composite order bilinear groups. In this paper, we propose the first efficient anonymous HIBE scheme with short ciphertexts in prime order (asymmetric) bilinear groups, and prove its security in the full model with an efficient reduction. To achieve this, we use the dual system encryption methodology of Waters. We also present the benchmark results of our scheme by measuring the performance of our implementation.