Revocable and Verifiable Key Aggregate Searchable Encryption for Flexible Data Sharing

With an increasing number of users storing vast amounts of data in cloud servers, effectively protecting and utilizing these private data has become a primary challenge today. In this context, Key Aggregation Searchable Encryption (KASE) achieves efficient sharing of various file types using a single key, thereby protecting data privacy while reducing user storage overhead and communication costs. However, existing schemes still face certain challenges. On the one hand, it is challenging to revoke search privileges for specific users when changes are required. On the other hand, semi-trusted cloud servers may return tampered search results, which seriously affects the user’s search experience. To address these issues, we propose a revocable and verifiable key aggregation searchable encryption scheme for flexible data sharing. The scheme utilizes the Shamir secret sharing technique and proposes a dynamic key sharing algorithm to achieve efficient privilege revocation through user key updates. In addition, we combine cryptographic accumulator and blockchain technology to propose a search result verification algorithm. The algorithm efficiently verifies the returned search results. Finally, we performed a comprehensive security analysis and performance evaluation of the proposed solution. The results demonstrate that our solution excels in both security and efficiency.