Blockchain Based Data Integrity Verification for Cloud Storage with T-Merkle Tree

Blockchain based verification has recently been studied as a new emerging approach for cloud data integrity protection without a centralized third party auditor. Existing schemes are mostly limited to scalability barrier and search efficiency of blockchain, which restricts their capability to support large-scale application. To address the problem above, we propose a blockchain based integrity verification scheme for large-scale cloud data using T-Merkle Tree. In our design, data tags are generated by ZSS short signature and stored on blockchain, and a new verification method based on ZSS short signature is proposed. The integrity of cloud data can be efficiently and undeniably verified with the property of bilinear pairing by offloading the computation from verifier to prover. Furthermore, a new blockchain storage structure called T-Merkle tree and its search algorithm is designed to improves the storage utilization and supports binary search in a block. Finally, a prototype system based on Hyperledger Fabric is implemented to evaluate our scheme. Theoretic analysis and experimental results demonstrate the security and efficiency of our proposed scheme.