Trusted edge and cross-domain privacy enhancement model under multi-blockchain

With its promising security and distributed qualities, blockchain offers a significant opportunity to break through the privacy protection issues in the edge computing paradigm. However, when edge participants submit security tasks to a distributed blockchain network across domains, they may expose their data privacy and location privacy. These privacy will be maliciously attacked and exploited by attackers such as external attackers and untrusted third parties, increasing the difficulty of access control. In addition, the performance bottleneck of blockchain systems cannot meet the demand for efficient data processing. To address these problems, we propose a cross-domain privacy enhancement scheme based on multi-blockchain. The scheme first integrates edge computing based on master-slave multi-blockchain and designs an identity authentication mechanism and trust assessment mechanism to deploy a three-layer trusted network architecture, which ensures the security stability and operational efficiency at the edge side. Secondly, role mapping rules are developed and trust degree is evaluated for domain nodes, and a cross-domain access control model based on trust degree and role is proposed. Data in this model cannot be exchanged across domains until all nodes jointly verify whether the access control policy is effective, which ensures the secure sharing of data in heterogeneous domains. In addition, to ensure the privacy and authenticity of data in cross-domain sharing, a hybrid searchable encryption method based on symmetric encryption and public key encryption is proposed. Finally, the security theoretical analysis proves that the model successfully ensures the non-repudiation of access control policy and the controllability of cross-domain data. Experiments show that the proposed model improves access dynamics by 74.8% and reduces CPU usage by 24.6% on average compared to traditional RBAC. The scheme is scalable, and its sending rate to throughput ratio reaches 1:1, gaining a 2X throughput advantage over existing schemes.