GBT-CHAIN: A System Framework for Solving the General Trilemma in Permissioned Blockchains

Abstract

As a subset of distributed systems, blockchain technology is equally bound by the CAP trilemma. Specifically, no distributed system can satisfy consistency, availability, and partition tolerance simultaneously. Informally, the innovative blockchain trilemma has been theorized to include security, scalability, and decentralization. While many software approaches on blockchains claim to solve the trilemma problem, almost all known approaches have been proven to involve tradeoffs and fail to reach the upper bounds, meaning they do not achieve the theoretical limit value in each term of a trilemma. In this article, we propose a general trilemma based on the above two trilemmas. For permissioned blockchains, we then describe a system framework called GBT-CHAIN to solve the G eneral B lockchain T rilemma. In the proposed framework, the consensus and data layer, the network layer, and the physical layer work in cooperation. According to our theoretical proof and experimental analysis, the three properties of the trilemma consisting of consistency, scalability, and partition tolerance are perfectly satisfied without tradeoffs. Our results demonstrate that the general blockchain trilemma is resolved by combining consensus algorithms and physical topologies, in particular for permissioned blockchains.