From the report:
“[…] With respect to security, expert assessments suggest a non-negligible probability that a cryptographically relevant quantum computer could emerge over the coming decade, although no such
system currently exists. In parallel, the possibility of “harvest-now, decrypt-later” attacks lighlight the importance of long-term data confidentiality, particularly for information that must remain secure well beyond current cryptographic lifecycles. These considerations underscore why quantum-related risks are increasingly incorporated into discussions on financial system resilience.

Several quantum-safe approaches are being developed to address these challenges. Post-quantum cryptography, supported by international standardisation efforts, is emerging as a central element of the transition toward quantum-resilient security. The implementation of post-quantum cryptography
is, however, not a simple substitution exercise. In practice, migration efforts may require inventorying cryptographic dependencies, testing compatibility with existing systems, and coordinating updates with external counterparties and service providers. This is the core position of the G7 Cyber Expert Group (CEG), who are supporting the coordination of post-quantum cryptography following the publication of its roadmap for transitioning to quantum-safe technologies in January 2026. Other approaches, including quantum-based communication techniques and symmetric key distribution architectures, may complement cryptographic solutions in specific contexts. These other options involve trade-offs related to technological maturity, scalability, interoperability, operational complexity and cost, suggesting that no single approach is universally applicable. […]”