An Efficient, Secure and Reliable Search Scheme for Dynamic Updates with Blockchain

Blockchain is a newly emerged technology to maintain data consistency through distributed network. Due to the nature of tamper-resistance, blockchain can well be used to achieve secure and reliable search without the participation of any third party. For data storage system with frequent updates, unfortunately, the existing blockchain-based search methods do not work. In this paper, we try to solve this problem by proposing a highly efficient search scheme for dynamic updates while still using blockchain to ensure security and reliability. Instead of modifying the original index directly, our updates are implemented by appending new indices when adding new data and maintaining a revocation list when deleting or changing data. Note that, the index tables and revocation list are preserved through dynamic searchable encryption, achieving high efficiency as well as security. Thus, attacker cannot learn if the newly added file contains a keyword that was searched before or not, so it can resist file-rejection attacks. Finally, we set up a blockchain-based search framework and validate the effectiveness and practicability of our method.