Insider Brief
- A G7 report warned that quantum technologies could eventually reshape financial security, payments and market infrastructure, prompting financial institutions to begin preparing for long-term risks and operational changes.
- The report identified post-quantum cryptography as the leading approach for protecting financial systems against future quantum-enabled attacks, while cautioning that migration will require complex coordination across interconnected systems and vendors.
- The G7 said quantum applications in areas such as portfolio optimization, fraud detection and macroeconomic modeling remain largely experimental, with significant technical, governance and concentration-risk challenges still unresolved.
The Group of Seven (G7) central banks warned that quantum technologies could reshape financial security and infrastructure over the coming decade, pushing banks, payment systems and regulators to begin preparing now for both cyber risks and new forms of computation.
In a 20-page report released by the G7 Central Bank Quantum Technologies Working Group, co-chaired by the Banque de France and the Bank of Canada, the group outlined how advances in quantum computing, communications and sensing could eventually affect everything from encryption and payment systems to financial modeling and market operations.
“Quantum technologies are progressing from fundamental research toward early forms of deployment, prompting growing attention across public institutions, financial authorities and the broader technology
ecosystem,” the analysts write. “These developments raise important questions for the financial system, particularly in areas where trust, security, resilience and long-term stability are critical.”
The report stops short of making predictions about when practical quantum computers will emerge or calling for specific regulations. Instead, the G7 presents what it describes as a “structured analytical framework” for understanding the risks, opportunities and trade-offs associated with quantum technologies as they move from laboratories into early-stage deployment.
At the center of the report is a growing concern within the financial sector that sufficiently advanced quantum computers could eventually break widely used cryptographic systems that underpin global banking, payments and digital communications.
The G7 noted that no “cryptographically relevant quantum computer” currently exists. But the report said expert assessments increasingly suggest there is a “non-negligible probability” such systems could emerge within the next decade, though timelines remain highly uncertain because of scientific and engineering hurdles.
That concern is especially important for financial institutions because of the long life span of sensitive data. The report highlights so-called “harvest-now, decrypt-later” attacks, in which encrypted information is intercepted and stored today with the expectation that future quantum systems could later decrypt it.
The report said the issue extends beyond confidentiality. Digital signatures used to authenticate transactions, verify identities and protect financial records could also become vulnerable over time if quantum systems are able to undermine current public-key cryptography.
The G7 working group argued that the threat differs from conventional cyberattacks because quantum computing targets the mathematical foundations of encryption itself rather than software bugs or operational mistakes.
Post-Quantum Migration
Much of the report focuses on post-quantum cryptography, or PQC, which refers to new encryption methods designed to resist attacks from quantum computers while still running on classical computer systems.
The report identifies PQC as the most practical and scalable near-term approach for improving quantum resilience across financial infrastructure.
The G7 pointed to ongoing standardization efforts led by the U.S. National Institute of Standards and Technology, which has spent years evaluating candidate quantum-safe algorithms for encryption and digital signatures.
But the report stresses that migrating to post-quantum cryptography will be far more complicated than a software upgrade.
Financial institutions often rely on deeply interconnected systems containing cryptographic components embedded across hardware, software, payment protocols and communications networks. The report said organizations may need to inventory cryptographic dependencies, test compatibility with legacy infrastructure and coordinate changes across vendors, counterparties and service providers.
During the transition period, multiple cryptographic systems may operate simultaneously, potentially creating interoperability and operational challenges.
The G7 Cyber Expert Group separately released a roadmap in January 2026 outlining migration considerations for organizations preparing for quantum-safe security systems.
The report also discusses complementary technologies beyond PQC, including Quantum Key Distribution, or QKD, and Distributed Symmetric Key Exchange architectures.
QKD uses the laws of quantum mechanics to create encryption keys in ways that can theoretically reveal whether communications have been intercepted. But the report notes that such systems remain expensive, infrastructure-heavy and difficult to scale because they often require dedicated fiber or satellite links.
The report frames these technologies not as universal replacements, but as tools that may be appropriate in specialized contexts involving highly sensitive communications.
Quantum Finance Still Experimental
Beyond cybersecurity, the G7 report examines how quantum technologies could eventually influence financial operations themselves.
Researchers and technology firms have spent years investigating whether quantum systems could improve optimization, simulation and machine learning tasks that are difficult for conventional computers.
Potential applications discussed in the report include portfolio optimization, risk analysis, fraud detection, liquidity management and large-scale economic modeling.
Still, the G7 repeatedly reports that most financial applications remain experimental and that classical systems continue to outperform quantum approaches in nearly all real-world settings.
The report describes quantum processors as specialized accelerators rather than replacements for conventional computers. In that sense, the technology is compared to graphics processing units, or GPUs, which are used today for artificial intelligence and scientific computing workloads.
One major research area involves optimization problems, which are common throughout finance. These problems can include portfolio construction, transaction routing and liquidity allocation across payment systems.
Quantum approaches such as the Quantum Approximate Optimization Algorithm and quantum annealing systems are being tested for these tasks. But the report said most experiments remain limited to small-scale or stylized models.
The G7 also examines quantum machine learning, which attempts to combine quantum computing with AI-related techniques such as pattern recognition and optimization.
The report said the goal is not to replace classical AI systems, but to explore whether certain computational sub-tasks could eventually benefit from quantum resources.
At the same time, the working group highlights “quantum-inspired” techniques — classical algorithms based on ideas from quantum physics — as a potentially more immediate development path because they can run on existing infrastructure without requiring quantum hardware.
Payments, Central Banks and Systemic Risks
The report devotes substantial attention to payment systems and central banking operations, areas where reliability and resilience are considered critical.
Researchers are exploring whether quantum optimization techniques could eventually improve liquidity management and settlement coordination in high-value payment systems. Quantum-assisted anomaly detection systems are also being studied for identifying fraud or operational disruptions in large transaction flows.
But the G7 again cautions that these applications remain early-stage research projects rather than deployable commercial systems.
Central banks themselves are investigating whether quantum technologies could eventually support macroeconomic simulations, financial stability modeling and stress-testing exercises.
The report said some quantum algorithms may theoretically accelerate Monte Carlo simulations or improve sampling from complex probability distributions used in financial analysis. Yet the paper stresses that methodological robustness, explainability and validation remain major obstacles.
The report also raises broader systemic concerns that extend beyond technical performance.
One issue is concentration risk. If advanced quantum capabilities eventually become commercially useful, access may be concentrated among a small number of cloud providers, hardware vendors or specialized software firms.
That could create shared dependencies across financial institutions, increasing exposure to outages, cyber incidents or supply-chain disruptions affecting a narrow group of providers.
The G7 also warned that some quantum-enhanced analytical systems could become difficult to interpret or audit, particularly when combined with advanced machine learning tools.
Skills shortages are another concern. The report notes that effective quantum preparedness requires expertise spanning physics, cryptography, cybersecurity, mathematics and financial systems — a combination that remains relatively rare.
Cautious Preparedness
The G7 adopts a cautious tone when considering quantum technology, avoiding the more aggressive predictions often associated with the quantum computing industry.
The report repeatedly states that quantum technologies are developing unevenly and that many proposed applications may never become practical or cost-effective.
Still, the working group argues that financial institutions cannot afford to ignore the technology because of the long timelines associated with cryptographic migration and infrastructure modernization.
Rather than advocating rapid deployment, the report frames preparedness as an ongoing process involving monitoring, governance, coordination and knowledge-sharing.
The G7 concludes that understanding uncertainty itself is one of the most important aspects of preparing for quantum technologies.
“Looking ahead, quantum technologies are likely to remain an area of sustained research and experimentation across scientific, industrial and institutional communities,” the analysts write. “Their relevance for the financial system will continue to depend on technological progress, standardisation efforts and governance practices, as well as on broader trends in digitalisation and data-intensive computing. In this evolving landscape, preparedness is best understood as an ongoing analytical effort rather than a fixed course of action. Continued monitoring, knowledge exchange and cross-sector dialogue will remain central to informed and coordinated assessment.”
