Blockchain-Based Reputation Management in Cyber-Physical Multi-Agent Systems Using Soulbound Tokens

Abstract

In cyber-physical multi-agent systems, ensuring secure and decentralized cooperation among autonomous agents is crucial for maintaining system integrity and operational reliability. However, the presence of malicious or selfish agents in these systems often disrupts message delivery and trust. This paper presents a blockchain-based reputation management framework that integrates adaptive trust scoring, decentralized relay selection, and non-transferable soulbound tokens to incentivize cooperation and build reputation. By combining off-chain trust evaluation with on-chain transparency through the PureChain permissioned blockchain, the framework achieves secure, tamper-proof reputation management. Experimental results show average trust score above 80% under varying proportions of malicious behavior (20% to 80%). The proposed PureChain blockchain also achieved approximately 7.7 times lower transaction latency and 1.4 times higher throughput compared to Ethereum Sepolia, making it suitable for resilient communication in cyber-physical multi-agent systems.