Date of Publication
By facilitating multiple independent owners to jointly control a distributed network, blockchain can be used to solve the problem of device collaboration in complex networks (e.g. 5G, health care industries) through a distributed consensus mechanism. However, the state-of-the-art blockchain-based solutions cannot meet the demand of high transaction rate for those applications, due to the unavoidable data synchronization cost in decentralized systems. To address this issue, recent research splits blockchain nodes into multiple groups as parallel shardings to improve scalability at the cost of increased communication and storage per node. This paper proposes a fast and secure distributed blockchain protocol to reduce the traffic complexity while enhancing the transaction rates and the capability of fault-toleration. We introduce Proof-of-Behavior (PoB), a behavior-based incentive mechanism, for stimulating honest behavior and neutralizing malicious attacks. We design a blockchain protocol by integrating PoB with Raft, another classic consensus protocol with supervision, called Beh-Raft-Chain. Our approach replaces Practical Byzantine Fault Tolerance (PBFT) with Behavior-based Raft to lower the traffic complexity to O(n) and boost the capability of fault-toleration from n/4 to n/3 , where n is the scale of blockchain. In our solution, we weigh all nodes based on their money and behaviors, and then set an adjustment parameter to increase the probability of candidate nodes being chosen beyond only a few nodes with the highest weight, in order to incentivize honest behavior in our mechanism. Our comparative experiments confirm Beh-Raft-Chain's theoretical low complexity and high fault-toleration properties.