Research on the privacy protection technology of blockchain spatiotemporal big data

Abstract At present, the fast-paced development of big data technology and the Internet of Things has led to the generation of spatiotemporal data streams on a large scale. In this circumstance, data holders often choose the cloud storage of their data to alleviate with the pressure of local storage and computing overhead. However, this is a centralized mode of storage, and the data is susceptible to the risk of tampering and leakage in the absence of physical control over spatio-temporal big data. Therefore, a blockchain-based space-time big data privacy protection scheme is devised in this paper. To begin with, in order to ensure data privacy, the scheme adopts a storage mode in which the public chain are coordinated with the side chain. The former stores various information such as keys and security authentication parameters, while the latter stores private data. Then, the irreversible SHA256 algorithm is applied to authenticate the access nodes. Finally, AES and RSA hybrid encryption is performed to encrypt the collected spatio-temporal big data for the security of private data to be further enhanced. The security performance of the system is evaluated by comparing the success rate of attacks on the blockchain under different circumstances. Also, the system throughput of this scheme is analyzed through simulation, the results of which show that the service life of this system reaches a minimum of 13.79 years when 100 nodes are use. In this context, the system throughput reaches 1607 transactions/s, each node contains 1.2×107 blocks, and the time taken to query specific spatio-temporal data is less than 2 seconds.