Cryptology ePrint Archive: Report 2014/994

Key-Policy Multi-authority Attribute-Based Encryption

Riccardo Longo and Chiara Marcolla and Massimiliano Sala

Abstract: Bilinear groups are often used to create Attribute-Based Encryption (ABE) algorithms. In particular, they have been used to create an ABE system with multi authorities, but limited to the ciphertext-policy instance. Here, for the first time, we propose a multi-authority key-policy ABE system. In our proposal, the authorities may be set up in any moment and without any coordination. A party can simply act as an ABE authority by creating its own public parameters and issuing private keys to the users. A user can thus encrypt data choosing both a set of attributes and a set of trusted authorities, maintaining full control unless all his chosen authorities collude against him. We prove our system secure under the bilinear Diffie-Hellman assumption. The final publication is available at

Category / Keywords: ABE, Bilinear groups, Algebraic cryptography

Original Publication (with major differences): Lecture Notes in Computer Science

Date: received 12 Dec 2014, last revised 8 Mar 2016

Contact author: riccardolongomath at gmail com

Available format(s): PDF | BibTeX Citation

Note: Updated paper to the published version.

Version: 20160308:144928 (All versions of this report)

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