RRChain is a public chain developed by RRC project team. RRChain adopts unique algorithm design (sandwich algorithm) and multiple algorithm sets. It can still ensure the fairness of mining under the premise of using PoW mechanism, relieving advantages of professional mining machines in order to ensure the fairness of ordinary users mining. Through a P2P network, computers, mobile phones, and other computing terminals are used to allow application-side users (demanders) to rent computing power (suppliers) to other users on the network. The computing power can accomplish certain tasks, such as big data analysis, artificial intelligence, image processing, game operations and many other aspects. As an important part of the RRC ecosystem, RRChain has played the following two key roles.