Blockchain-powered distributed data auditing scheme for cloud-edge healthcare system

Cloud-edge healthcare system provides storage and computing functions at the hospital servers, bringing low latency for doctors and patients. However, hospital servers cannot be trusted and have limited computing resources. Data integrity verification for the cloud-edge healthcare system is an urgent concern. To this end, we proposed a data integrity auditing scheme based on blockchain. First, a distributed data integrity verification method without a third-party auditor is designed. The data are divided into smaller parts and hashed into a hash table. The verification tag is constructed according to the column of the hash table and secret string generated by a pseudo-random function. Then, a detailed blockchain-based data integrity auditing scheme is proposed, including Proof of Auditing Frequency and block structure. Besides, a security analysis for the common attacks is given. Finally, the proposed scheme is evaluated against two start-of-the-art schemes in a simulated cloud-edge healthcare system. The results demonstrate that the proposed scheme can verify data integrity without losing efficiency.