EABDS: Attribute-Based Secure Data Sharing with Efficient Revocation in Cloud Computing

Ciphertext-policy attribute-based encryption (CP-ABE) is becoming a promising solution to guarantee data security in cloud computing. In this paper, we present an attribute-based secure data sharing scheme with Efficient revocation (EABDS) in cloud computing. Our scheme first encrypts data with Data encryption key (DEK) using symmetric encryption and then encrypts DEK based on CP-ABE, which guarantees the data confidentiality and achieves fine-grained access control. In order to solve the key escrow problem in current attribute based data sharing schemes, our scheme adopts additively homomorphic encryption to generate attribute secret keys of users by attribute authority in cooperation with key server, which prevents attribute authority from accessing the data by generating attribute secret keys alone. Our scheme presents an immediate attribute revocation method that achieves both forward and backward security. The computation overhead of user is also reduced by delegating most of the decryption operations to the key server. The security and performance analysis results show that our scheme is more secure and efficient.