Efficient Multi-Authority Attribute-Based Encryption with Policy Hiding and Updating

Attribute-based encryption (ABE) is a popular cryptographic technology to guarantee data security in the Internet of things (IoTs). However, the single attribute authorization in traditional ABE scheme is tasked with costly calculations, which will become a bottleneck in IoTs. Besides, access policy in a plaintext form may reveal personal information. In addition, data owners need to have flexibility to change access policy. In this paper, we propose a multi-authorization attribute encryption scheme that supports policy hiding, policy updating and ciphertext validation. In our scheme, the computational cost of ciphertext decryption is constant, which reduces computational overhead and storage usage. Security analyses prove that our scheme realizes the security in static security model and anti-collusion attack model. Finally, we demonstrate that the performance of the scheme is more efficient than previous ABE schemes.