Abstract: Aiming at the problem of revoking the access rights of the ciphertexts policy attribute base encryption shared data in the cloud environment,the revocation scheme based on attribute was proposed.In the scheme,the trusted third party searches the attribute set satisfying the ciphertext access structure from the user attribute set with the global identity,generates the key component with the same global identity for each attribute in the intersection,and generates the user private key by combining the key components.When the revocation is occured,the scheme updates the key component which revokes the user attribute and distributes the component to other users who have the same attribute.At the same time,the corresponding re-encryption key is generated,and the ciphertext is re-encrypted in the cloud environment.The security analysis and experiments show that the scheme is safe to choose plaintext,which can effectively realize the real-time cancellation of attributes and solve the synchronization problem of multi-authorization structure key distribution.The hash function is used to make the ciphertext length constant,thus reducing the resource cost and mee-ting the application requirements of security in the real cloud environment.

Key words: Attribute encryption, Attribute revocation, Cloud environment, Resource overhead, Single trusted third party