Revocable attribute-based proxy re-encryption
Attribute-based proxy re-encryption (ABPRE), which combines the notions of proxy re-encryption (PRE) and attribute-based encryption (ABE), allows a semi-trusted proxy with re-encryption key to transform a ciphertext under a particular access policy into a ciphertext under another access policy, without revealing any information about the underlying plaintext. This primitive is very useful in applications where encrypted data need to be stored in untrusted environments, such as cloud storage. In many practical applications, and in order to address scenarios where users misbehave or the re-encryption keys are compromised, an efficient revocation mechanism is necessary for ABPRE. Previously, revocation mechanism was considered in the settings of identity-based encryption (IBE), ABE, predicate encryption (PE), and broadcast PRE, but not ABPRE, which is what we set to do in this paper. We first formalize the concept of revocable ABPRE and its security model. Then, we propose a lattice-based instantiation of revocable ABPRE. Our scheme not only supports an efficient revocation mechanism but also supports polynomial-depth policy circuits and has short private keys, where the size of the keys is dependent only on the depth of the supported policy circuits. In addition, we prove that our scheme is selectively chosen-plaintext attack (CPA) secure in the standard model, based on the learning with errors assumption.
Other Information
Published in: Journal of Mathematical Cryptology
License: http://creativecommons.org/licenses/by/4.0
See article on publisher's website: https://dx.doi.org/10.1515/jmc-2020-0039
Funding
Open Access funding provided by the Qatar National Library.
History
Language
- English
Publisher
De GruyterPublication Year
- 2021
License statement
This Item is licensed under the Creative Commons Attribution 4.0 International License.Institution affiliated with
- Hamad Bin Khalifa University
- College of Science and Engineering - HBKU