Attribute-Based Proxy Re-Encryption with Constant Size in Cloud Computing

With its powerful storage and computing resources, cloud computing can efficiently process large-scale data and perform complex computing tasks. However, secure data sharing in the cloud faces significant challenges. Attribute-based encryption is a feasible mechanism. Hence, we propose an attribute-based proxy re-encryption with constant size ciphertexts. This delegates the service provider to convert ciphertext under the original access structure into ciphertext accessible to users who were not previously specified. The scheme satisfies fine-grained data security sharing and the delegation of decryption permission to other authorized users. By outsourcing a large number of time-consuming computing tasks to cloud service provider, the user’s computational burden is significantly reduced. Moreover, security analysis demonstrates that this scheme satisfies the security requirements of data sharing in cloud.