### Simplified Revocable Hierarchical Identity-Based Encryption from Lattices

Shixiong Wang, Juanyang Zhang, Jingnan He, Huaxiong Wang, and Chao Li

##### Abstract

As an extension of identity-based encryption (IBE), revocable hierarchical IBE (RHIBE) supports both key revocation and key delegation simultaneously, which are two important functionalities for cryptographic use in practice. Recently in PKC 2019, Katsumata et al. constructed the first lattice-based RHIBE scheme with decryption key exposure resistance (DKER). Such constructions are all based on bilinear or multilinear maps before their work. In this paper, we simplify the construction of RHIBE scheme with DKER provided by Katsumata et al. With our new treatment of the identity spaces and the time period space, there is only one short trapdoor base in the master secret key and in the secret key of each identity. In addition, we claim that some items in the keys can also be removed due to the DKER setting. Our first RHIBE scheme in the standard model is presented as a result of the above simplification. Furthermore, based on the technique for lattice basis delegation in fixed dimension, we construct our second RHIBE scheme in the random oracle model. It has much shorter items in keys and ciphertexts than before, and also achieves the adaptive-identity security under the learning with errors (LWE) assumption.

Available format(s)
Category
Public-key cryptography
Publication info
Published elsewhere. MINOR revision.CANS 2019 (The 18th International Conference on Cryptology and Network Security)
Keywords
LatticesIdentity-based encryptionRevocationDelegation
Contact author(s)
wsx09 @ foxmail com
History
Short URL
https://ia.cr/2019/917

CC BY

BibTeX

@misc{cryptoeprint:2019/917,
author = {Shixiong Wang and Juanyang Zhang and Jingnan He and Huaxiong Wang and Chao Li},
title = {Simplified Revocable Hierarchical Identity-Based Encryption from Lattices},
howpublished = {Cryptology ePrint Archive, Paper 2019/917},
year = {2019},
note = {\url{https://eprint.iacr.org/2019/917}},
url = {https://eprint.iacr.org/2019/917}
}

Note: In order to protect the privacy of readers, eprint.iacr.org does not use cookies or embedded third party content.