Abstract:

Achieving secure data sharing in an untrusted environment is always a difficult problem. Traditional centralized solutions have problems that data is easily leaked, data is easily tampered, data destination is difficult to track, and supervision is difficult. Data sharing scheme based on public-key system has some problems such as high communication cost, high computation cost and poor practicability. To solve the above problems, this paper proposes a data sharing scheme based on blockchain. The scheme maintains a credible ledger through the blockchain to ensure the traceability of data and immutability of the access control authority. On this basis, a proxy re-encryption scheme based on Schnorr is constructed, which realizes the secure data sharing by a proxy re-encryption secret key. Compared with the traditional schemes, the proposed scheme has better security and traceability, and has been successfully applied in the medical data sharing project.

Key words: blockchain, proxy re-encryption, data sharing, Schnorr algorithm