Multi-Blockchain Model for Central Bank Digital Currency

Digital Currency for Central Bank is becoming an important policy for country. CBDC (Central Bank Digital Currency) model should take advantages in the supervision, payment and consumption. Blockchain possesses the feature of de-centrality, tamper-resistant, and traceability. So this paper attempts to use the blockchain as the fundamental technology of CBDC. However, the challenges such as the protection for users privacy, supervision and transaction speed should be overcome. This paper proposes a CBDC model called MBDC which is based on the permission blockchain technology. The model makes use of the multi-blockchain architecture and ChainID to improve the models scalability and process payments more quickly. In this model, central bank and commercial banks and other agencies build and maintain the blockchain. On one hand, central bank could master the issuance of currency. On the other hand, relying on the user account address protocol, central bank could separate the users identity and transaction information. In this way, central bank could avoid double-spending issues and protect users privacy. In addition, the establishment of DC (Data Center) and layers of supervision provide strong supervision for the model. Finally, we also demonstrate, both theoretically and experimentally, the performance of model on the scalability and the speed of transaction execution etc.