Paper 2016/262

Collaborative Multi-Authority Key-Policy Attribute-Based Encryption for Shorter Keys and Parameters

Riccardo Longo and Chiara Marcolla and Massimiliano Sala

Abstract

Architectures relying on a single central authority often offer a great efficiency, but suffer of resiliency problems and are quite vulnerable to attacks. In our proposal, a Multiple-Authorities Key-Policy Attribute-Based Encryption scheme is constructed including a collaboration phase between the authorities, in order to achieve shorter keys and parameters, thus enhancing the efficiency of encryption and decryption. \\ We prove our system secure under a variation of the bilinear Diffie-Hellman assumption, providing a lower bound on its complexity.

Note: Minor improvements and typos correction.