Abstract:

Valuable data are uploaded to the cloud for sharing by users in the age of big data, which requires more secure and reliable cloud storage services. At present, cloud storage service guarantees data security through distributed storage, but cloud data is still concentrated in storage service providers, and data integrity verification depends on third party. In addition, the traditional cloud storage mode relies on the equipments of service providers and does not make full use of the idle storage space of users. This paper proposes a distributed storage system based on blockchain consensus mechanism and its characteristic of decentralization. The system establishes incentive mechanism to encourage all network nodes to participate in data storage services, improves the utilization of network storage space, and introduces smart contracts to ensure fairness of data services. Comparing with other blockchain-based distributed storage systems, the storage proof of the proposed system is concise and efficient, which can realize the on-chain and off-chain data retrieval and public data integrity verification, and can ensure the fairness of off-chain micro-payment. The security analysis and contract test results show that the system can achieve fair data storage, retrieval and public integrity verification.

Key words: distributed cloud storage, blockchain, smart contract, fair payment, public verification