Forward-Secure Fine-Grained Proxy Re-Encryption Scheme
摘要
With the rapid development of cloud computing and big data technologies, data privacy protection and secure, efficient sharing have become critical issues. Proxy Re-Encryption (PRE) technology enables secure sharing of data among different users by delegating a proxy to transform the encrypted data without leaking the plaintext information. However, existing PRE schemes are insufficient in achieving fine-grained access control of data and addressing the risks of long-term key leakage. To tackle these problems, this paper proposes a Forward-Secure Fine-Grained Proxy Re-Encryption (FS-FPRE) Scheme. Firstly, Attribute-Based Encryption (ABE) technology is used to achieve fine-grained access control for data. Secondly, the system is divided into multiple time periods, and binary tree is used to manage these time periods to ensure the efficiency and scalability of key update. A dedicated key update algorithm is designed to update the key periodically to realize the periodic management of the key. During encryption, the period information is embedded in the ciphertext to reduce the risk brought by the private key leakage, and the scheme achieves forward security because the whole key update is unidirectional and the ciphertext is bound to the time period. Finally, under the \((q-1)\) DBDHE assumption, the scheme is proven to be IND-FS-CPA secure.