A Blockchain-Based Proxy Re-Encryption Scheme with Conditional Privacy Protection and Auditability

With the development of Internet of Things technology, intelligent door lock devices are widely used in the field of house leasing. In the traditional housing leasing scenario, problems of door lock information disclosure, tenant privacy disclosure and rental contract disputes frequently occur, and the security, fairness and auditability of the housing leasing transaction cannot be guaranteed. To solve the above problems, a blockchain-based proxy re-encryption scheme with conditional privacy protection and auditability is proposed. The scheme implements fine-grained access control of door lock data based on attribute encryption technology with policy hiding, and uses proxy re-encryption technology to achieve auditable supervision of door lock information transactions. Homomorphic encryption technology and zero-knowledge proof technology are introduced to ensure the confidentiality of housing rent information and the fairness of rent payment. To construct a decentralized housing lease transaction architecture, the scheme realizes the efficient collaboration between the door lock data ciphertext stored under the chain and the key information ciphertext on the chain based on the blockchain and InterPlanetary File System. Finally, the security proof and computing performance analysis of the proposed scheme are carried out. The results show that the scheme can resist the chosen plaintext attack and has low computational cost.