MGRS-PBFT: An Optimized Consensus Algorithm Based on Multi-Group Ring Signatures for Blockchain Privacy Protection

In the realm of blockchain systems, the prominence of privacy and security issues is steadily increasing, thereby necessitating greater focus on privacy protection technologies. The conventional practical Byzantine fault tolerance (PBFT) consensus algorithm is characterized by limited scalability and an absence of privacy protection. Consequently, this study introduces ring signature privacy protection technology and proposes an enhanced PBFT consensus algorithm, named MGRS-PBFT, based on multi-group ring signatures, aimed at bolstering blockchain privacy protection. Firstly, a credit score mechanism is introduced to incentivize or penalize nodes’ behavior and assess their performance. The selection of the primary node is determined through a voting process utilizing the nodes’ credit scores, thereby mitigating the influence of malicious nodes within the system and enhancing overall system security. Secondly, nodes are stratified into multiple groups based on inter-node response speed, thus streamlining the consensus protocol and diminishing system communication complexity. Finally, an identity-based ring signature algorithm is implemented to protect the privacy data of nodes. Experimental results demonstrate that the average consensus delay of MGRS-PBFT is reduced by 46.73% compared to PBFT, 20.87% compared to double-layer PBFT, 18.61% compared to SG-PBFT, and 27.58% compared to CRBFT. Additionally, MGRS-PBFT achieves an average throughput that is 2.44 times that of PBFT, 1.27 times that of double-layer PBFT, 1.23 times that of SG-PBFT, and 1.45 times that of CRBFT. Through security experiments, the analysis demonstrates that MGRS-PBFT outperforms PBFT in terms of its resistance to Byzantine nodes and fault tolerance.