VQL: Efficient and Verifiable Cloud Query Services for Blockchain Systems

Despite increasingly emerging applications, a primary concern for blockchain to be fully practical is the inefficiency of data query. Direct queries on take much time by searching every block, while indirect database greatly degrade authenticity query results. To conquer problem, we propose Verifiable Query Layer (VQL) that can deployed in cloud provide both efficient and verifiable services systems. The middleware layer extracts from underlying system efficiently reorganizes them databases. prevent falsified being stored middleware, cryptographic fingerprint calculated based each constructed database. will first verified miners then written into blockchain. Moreover, public users verify entire databases or several interest layer. We implement VQL together with verification schemes conduct extensive experiments system. evaluation results demonstrate support various guarantee