Attribute-based Authenticated Key Exchange Protocol in Multiple Attribute Authorities Environment

Available Attribute-Based Authenticated Key Exchange (ABAKE) protocols are all designed in the single Attribute Authority (AA) environment. However, secure communication is in demand between parties from different Attribute Authorities (AAs). Based on Waters attribute-based encryption scheme, an ABAKE protocol is proposed in multiple AAs environment and the security of the proposed protocol is reduced to Gap Bilinear Diffie-Hellman (GBDH) and Computational Diffie-Hellman (CDH) assumptions in the Attribute-Based extended Canetti-Krawczyk (ABeCK) model. Moreover, the scheme, which transmits attribute authentication policy represented by linear secret sharing scheme via Boolean formulas, can express flexible policies and decrease communication cost drastically.