Finance as Critical Infrastructure: Embedding Post-Quantum Cryptography in Digital Finance Architectures

Quantum computing presents both transformative potential and unprecedented risk. Financial systems, which rely on RSA, ECC, and other public-key cryptography, are especially vulnerable to quantum-enabled attacks. For the United States—where the IRS, Treasury, Federal Reserve, Medicare, and unemployment programs collectively manage trillions of dollars annually—the implications are profound. This paper argues that finance must be treated as critical national infrastructure and proactively secured against the quantum threat. Post-Quantum Cryptography (PQC), as being standardized by NIST, offers the technical foundation for resilience. However, successful adoption requires more than technical substitution—it demands an architecture-led redesign. Drawing on the Finance Architecture Strategy Technology (FAST™) framework, which embeds compliance and fraud prevention into design, and the Digital Finance Reference Architecture (DFRA™), a modular blueprint for cloud-native, scalable transformation, we propose a roadmap for embedding PQC into digital finance. This includes PQC integration within cloud ERP platforms such as SAP S/4HANA, hybrid cryptography strategies during transition, and governance models that align with OMB A-123 and DHS critical infrastructure protection. By combining PQC with structured frameworks, the U.S. can safeguard financial flows against future quantum adversaries, protect public trust, and reinforce its leadership in global digital governance. This work positions digital finance architecture as both an economic enabler and a national security priority, demonstrating how U.S. financial systems can be future-proofed for the quantum era.