PolyChain: A Generic Blockchain as a Service Platform

In recent years, blockchain technology has been attracting intensive attention from both the industries and academia because of its capability of rebuilding trust in trustless environments. There are increasing demands for developing and delivering blockchain applications and services in an agile and continuous way. To this end, Blockchain as a Service (BaaS) emerges which refers to cloud-based blockchain infrastructure developed by a vendor allowing users to develop, host, and use their own blockchain components, functions, and applications. There are many BaaS platforms developed by industries and academia, e.g., Bitcoin, Ethereum, and Hyperledger Fabric. However, they are either limited in scalability or difficult for configuration and customization. In this paper, we propose and develop PolyChain, a generic BaaS platform with high modularity, flexibility, scalability, reliability, and security, which are achieved with the following three design principles. First, each blockchain node is designed as four modularized components, e.g., network, storage, consensus, and application, based on the functionalities. Second, the components in a logic blockchain node interact via communication interfaces and can be deployed on different physical nodes. Finally, the component deployment is optimized based on the capabilities of the physical nodes. We believe PolyChain may benefit the industries and academia in agile development and continuous delivery of blockchain prototypes and applications.