Bank for International Settlements (BIS) Innovation Hub Swiss Centre unveils Project Tourbillon, showcasing revolutionary retail CBDC with enhanced anonymity. Pioneers new privacy concept to safeguard buyer identities, leveraging quantum-safe cryptography for future-proof security while awaiting speed upgrades.

The Bank for International Settlements (BIS) Innovation Hub Swiss Centre has unveiled Project Tourbillon, an experimental retail central bank digital currency (CBDC) design that focuses on the trade-offs between privacy, security and scalability in digital payments. Updated in November 2023, the project delivers two CBDC prototypes based on an eCash-style model that preserve the existing two-tier banking system while testing how a central bank could offer cash-like digital payments that still meet regulatory and security requirements. The work was carried out with the Swiss National Bank and builds on designs proposed by cryptographer David Chaum and economist Thomas Moser. Tourbillon’s core innovation is a new privacy paradigm of “payer anonymity”, under which the person making a payment remains anonymous to all parties, including the merchant, commercial banks and the central bank, while the payee (for example, the merchant) remains identifiable to their bank. This aims to mimic the anonymity of cash for consumers but still allow auditability and monitoring of receipts, which is important for limiting tax evasion and illicit finance. To secure the system against current and future threats, the prototypes implement quantum‑safe blind signatures and related cryptography, demonstrating that such techniques are feasible but currently impose significant performance costs: tests show payment latency rising by around a factor of five and throughput falling by roughly a factor of 200 compared with conventional cryptography. As a result, BIS positions Tourbillon as a first step and calls for further research on quantum‑safe methods and scalability, highlighting that privacy-preserving, future‑proof CBDC designs are technically possible but not yet ready for high‑volume production use.

✨ AI-generated background, compiled from web sources — not editorial content.

More coverage

• [PDF] Project Tourbillon - SNB (snb.ch)
• Project Tourbillon: exploring privacy, security and scalability for ... (bis.org)
• Project Tourbillon: Privacy, Security and Scalability for Retail CBDCs (iif.com)
• BIS Innovation Hub work on central bank digital currency (bis.org)
• BIS Innovation Hub projects - Bank for International Settlements (bis.org)

Explore the topic

• Switzerland
• Privacy
• BIS
• Retail