LBFT: An Asynchronous Committee-Based Blockchain Storage Strategy on Zero Trust Model

Abstract

The high storage costs brought by the full-replication storage strategy adopted in most existing blockchain systems have become the main bottleneck to system scalability. To address the above, we propose an asynchronous committee-based blockchain storage strategy named lightweight BFT (LBFT), which can be applied to more diverse scenarios with better system performance. It is the first blockchain storage scheme that is designed on the conception of the zero-trust model, achieving higher-level security and fending off internal, as well as external attackers. In addition, it makes the following progress on system performance on the premise of maintaining the merits of the blockchain: (1) decreases communication complexity by involving only a part of the nodes in each decoding round; (2) enhances the robustness of the scheme regardless of the time assumption of the network; (3) improves the computational efficiency in the encoding and decoding process; and (4) reduces the storage costs and improves system scalability. In addition, we implemented experiments on LBFT and two other existing blockchain-based storage strategies, and the experimental results showed that LBFT indeed has significant improvements in system performance.