Tourbillon is an innovative project designed to enhance cyber resiliency, scalability, and privacy in the context of a prototype Central Bank Digital Currency (CBDC). Launched by the BIS Innovation Hub’s Swiss Centre, the project aims to complete the prototype by mid-2023, with findings that will be applicable to both wholesale and retail CBDC applications.
CBDCs often necessitate trade-offs among cyber resiliency, scalability, and privacy. Tourbillon seeks to address these challenges by integrating technologies such as blind signatures and mix networks, alongside research in cryptography and CBDC design from experts like David Chaum, the inventor of eCash, and Thomas Moser, an alternate member of the Governing Board at the Swiss National Bank, as highlighted in the recent eCash 2.0 study.
To enhance cyber resiliency, the project will explore quantum-resistant cryptography. For scalability, it will implement an architecture that is compatible with distributed ledger technology but does not rely on it. By ensuring each transaction operates independently, the project aims for linear scaling of system resources, verifying the design’s scalability under realistic conditions.
Tourbillon also focuses on privacy measures that protect the identity of the payment sender while ensuring the recipient’s information remains visible for regulatory and compliance purposes.
Morten Bech, head of the BIS Innovation Hub Swiss Centre, remarked, “Digital central bank money can improve payments by making them better and more inclusive. However, creating a CBDC involves intricate trade-offs between cyber resilience, scalability, and user privacy. Project Tourbillon will develop and test a prototype that navigates these trade-offs and advances the technological capabilities of central banks.”