Fast and secure consortium blockchains with lightweight block verifiers

Due to advantages of moderate cost and easy deployment, consortium blockchains have been widely adopted in various commercial services and industrial applications. Nevertheless, because of limited number of miners, consortium blockchains are vulnerable to collusion attacks incurred by compromised block verifiers, i.e., miners verifying new blocks. To address this issue, edge devices acting as lightweight nodes can be recruited as lightweight block verifiers (LBVs) to verify the blocks together with typical miners. This increases the number of block verifiers, thereby enhancing blockchain security, but may result in a larger block verification delay. To tackle this dilemma, in this paper, we propose a computing resource management scheme to maximize the system utility related to users' satisfaction with the blockchain services, which aims at jointly optimizing computing resources of miners and LBVs. We prove the existence and uniqueness of the optimal set of strategies of miners and LBVs, and then exploit Karush-Kuhn-Tucker (KKT) conditions to find these strategies. The numerical results demonstrate that, compared with existing schemes, the proposed scheme achieves secure block verification by involving LBVs with optimized block verification delay.