Blockchain-based Private Set Intersection Protocol with Attribute-based Access Control

With the rise of cloud computing, many users outsource their data to be stored in cloud servers, enjoying the convenience while facing many security issues. In the field of secure multiparty computing, traditional privacy set intersection protocol data users use cloud servers for their data outsourcing to operate for calculating the intersection, the data is susceptible to tampering by the cloud servers, and the data users do not formulate fine-grained access control policies. To solve the above problems, this paper combines blockchain with privacy set intersection for the first time, and proposes a blockchain-based privacy set intersection protocol with attribute access control. This scheme utilizes blockchain instead of a cloud server as a trusted third party, data users utilize smart contracts to compute intersection via OPRF, and attribute encryption is used to provide access control for privacy set intersection protocol. Thus, it solves the risk of data vulnerability to tampering. This paper analyzes the security of the scheme and conducts simulation experiments.