SEM-DT: A Secure and Efficient One-to-Many Data Trading Scheme Based on Blockchain

The cutting-edge technology in computers has given big data more and more value, thus giving rise to data trading. To address the insecurity and inefficiency of the existing data trading schemes that are aimed at one-to-one trading, a one-to-many distributed data trading scheme is proposed, which allows a data seller to sell one piece of data to multiple buyers simultaneously but only needs to upload one piece of data as well as generate a single transaction, thus saving storage and computing resources. Firstly, a trading framework based on consortium blockchain is proposed to store transaction information and data flow records so that the transaction cannot be tampered with and can be traced back to the source. Then, the attribute-based searchable encryption technology is further improved to construct a data circulation scheme that realizes end-to-end encryption of data and ensures data security and efficient access. The experiment's findings demonstrate that, in comparison to one-to-one trading, this data trading scheme gradually becomes more efficient as the number of buyers (n) rises over 2, and when n = 35, the run time is less than a tenth of the former. Additionally, this scheme can perform better with larger amounts of data.