A Multi-blockchain Based Reliable Noise Adding Method for Privacy Preservation in Cyber-Physical Systems

Privacy preservation is an enabling technology for applications in cyber-physical systems. Noise adding is one of the popular methods to efficiently achieve effective privacy preservation. However, the strength of privacy preservation may be degraded for the noise-adding methods since the historical information of the malicious nodes cannot be tracked during the noise-adding process. To address this issue, in this paper, we apply a multi-blockchain to design a reliable noise-adding (RNA) method to strengthen the privacy preservation level. First, a multi-blockchain architecture is developed to ensure the traceability of the noised information, and avoid the information being impersonated, tampered with, and denied. The nodes are clustered into multiple groups so as to integrate the multi-blockchain architecture with zero-sum noise adding mechanism. Then, the proposed RNA method is analyzed in terms of correctness, privacy, and efficiency. The performance evaluations show that the proposed RNA method has advantages in protecting privacy, ensuring correctness, and reducing computational and communication costs.