A Prototype for Two-tier Central Bank Digital Currency (CBDC)(22.10月)/ BIS
In the era of digitisation, central banks stand before a choice: does retail central bank money need to go digital and, if so, how? Jointly embarking on the challenge to design a full-stack central bank digital currency (CBDC) system, the Bank for International Settlements (BIS) Innovation Hub Hong Kong Centre and the Hong Kong Monetary Authority (HKMA) dubbed the project “Aurum”, the Latin word for gold, reflecting our starting premise that digital currency issued under the auspices of a central bank must be as robust and trustworthy as gold. Through the creation of a technology stack comprised of: (1) a wholesale interbank system in which the wholesale CBDC (wCBDC) is issued to banks for onward distribution to retail users, and (2) a retail e-wallet system in which the retail CBDC (rCBDC) circulates among retail users, we set a goal to bring to life two very different types of retail tokens: (a) intermediated CBDC, also referred to herein as CBDC-tokens, and (b) CBDC-backed stablecoins, or in short, stablecoins. Given the complexity of the endeavour, the project was executed in partnership with the Hong Kong Applied Science and Technology Research Institute (ASTRI). We are glad to report that after a year of development, the prototype system was successfully completed. The present report provides an overview of the Aurum technology architecture. It is presented at a more technical level, supplemented by user interface visualisations, and should best be read in conjunction with the three e-HKD papers1 , as well as with the extensive body of foundational research issued by the BIS.2 The Aurum system is accompanied by technical manuals totalling over 250 pages that, together with the source code, are made accessible to all BIS central bank members on BIS Open Tech to serve as a public good that furthers the study of rCBDC architectures. The Aurum prototype also provides a solid basis for furthering the exploration and testing of e-HKD design in Hong Kong. Against this backdrop, we have no doubt that the Aurum prototype will catalyse and inspire the global quest for the most suitable rCBDC architecture.