Multi-Authority Attribute Based Encryption With Policy-hidden and Accountability

In this paper, an attribute-based encryption scheme with policy hidden and key tracing under multi-authority is proposed. In our scheme, the access structure is embedded into the ciphertext implicitly and the attacker cannot gain user's private information by access structure. The key traceability is realized under multi-authority and collusion is prevented. Finally, based on the DBDH security model, it is proved that this scheme can resist the plaintext attack under the standard model.