A Novel Fair and Verifiable Data Trading Scheme

With the widespread use of smart devices, a huge volume of data is generated every day, which is helpful for device user and device enterprises. However, the data generated by the smart device contains the user’s privacy, and the data is easy to be modified, forged, which requires a suitable scheme to protect the privacy of the data seller, the authenticity of the data, the fairness during the data trading process. In order to solve the problems, we design a novel fair and verifiable data trading scheme by combining hash function, signature, oblivious transfer, smart contract and private blockchain. The hash function is used for data integrity, the signature is used for the source of the data, the oblivious transfer is used for data verification, the smart contract is used for the encryption key trading, and the private blockchain is used as a ledger for the verification record, trading record and user reputation. The performance analysis shows that our scheme has enough features to help users complete data trading, and our scheme provides an extra function, the reputation record of users to reduce the possibility of user being deceived. The security analysis shows that our scheme provides IND-CCA security, anonymity, and has the capability of resisting collusion attack and data seller fraud. The fairness and practicability of the scheme are verified by simulation.