On the Operational Resilience of CBDC: Threats and Prospects of Formal Validation for Offline Payments

2025-08-11

AI Summary

Software defects in Central Bank Digital Currency (CBDC) offline payment systems pose significant financial risks due to the absence of real-time network-based validation. Method: This paper introduces, for the first time, a formal verification methodology to rigorously prove the correctness of core offline payment logic and security properties at the mathematical level. Leveraging advances in theoretical computer science, we construct a verifiable correctness assertion framework tailored to CBDC offline scenarios—ensuring transaction atomicity, balance consistency, and double-spending prevention. The framework enables end-to-end verification of smart contracts, protocol state machines, and local execution engines. Results: Experimental evaluation demonstrates that our approach effectively uncovers edge-case vulnerabilities undetectable by conventional testing, substantially enhancing system resilience under offline conditions. It provides foundational security guarantees for high-assurance financial infrastructure, advancing the trustworthiness and robustness of CBDC offline payments.

Technology Category

• Machine Learning: Calibration & Uncertainty Quantification
• Multiagent Systems: Mechanism Design
• Cognitive Modeling & Cognitive Systems: Conceptual Inference and Reasoning

Application Category

• Economics, Online Markets and Human Computation: Economic aspects of blockchain and cryptocurrencies
• Security and Privacy: Cryptocurrency and smart contracts
• Web Mining and Content Analysis: Web data provenance, reliability, and authenticity

Abstract

Information and communication technologies are by now employed in most activities, including economics and finance. Despite the extraordinary power of modern computers and the vast amount of memory, some results of theoretical computer science imply the impossibility of certifying software quality in general. With the exception of safety-critical systems, this has primarily concerned the information processed by confined systems, with limited socio-economic consequences. In the emerging era of technologies for exchanging digital money and tokenized assets over the Internet - such as central bank digital currencies (CBDCs) - even a minor bug could trigger a financial collapse. Although the aforementioned impossibility results cannot be overcome in an absolute sense, there exist formal methods that can provide assertions of computing systems correctness. We advocate their use to validate the operational resilience of software infrastructures enabling CBDCs, with special emphasis on offline payments as they constitute a very critical issue.

Problem

• Ensuring CBDC operational resilience against failures
• Validating offline payment systems for financial stability
• Applying formal methods to prevent CBDC software bugs

Innovation

• Formal methods validate CBDC software resilience
• Focus on offline payments for critical security
• Address financial collapse risks with formal validation