Decentralization attribute-based encryption method supporting complete policy hiding

The invention discloses a decentralized attribute-based encryption method supporting complete strategy hiding. The decentralized attribute-based encryption method adopts a decentralized multi-authority attribute-based encryption model to realize efficient privacy protection of data and user information. First, a plurality of authorizations are set to avoid single point failure and key escrow problems. And secondly, anonymizing the attributes to realize a completely hidden access strategy so as to guarantee the privacy of the user. In the process, a reusable ciphertext pool and a cloud proxy server are respectively utilized by the method to reduce the computing cost of the encryption and decryption stages of the user. Finally, user information is uniquely bound with leaf nodes in the binary tree, malicious users are tracked through the leaf nodes, and the malicious users are revoked through partial ciphertext updating. The invention designs a multifunctional, safe and efficient attribute-based encryption schem