While quantum computing promises major benefits, it also poses a less visible but very real security risk that organisations must address today. This is not a distant, theoretical problem that will only emerge in the next decade. For businesses' most sensitive data, the threat has already arrived in the form of a simple strategy known as “Harvest Now, Decrypt Later” (HNDL). In HNDL attacks, adversaries capture and store encrypted data with the intention of decrypting it once cryptographically relevant quantum computers exist.
Major cybersecurity agencies cite HNDL as the rationale for action: The U.S. Department of Homeland Security, the UK's National Cyber Security Centre, the European Union Agency for Cybersecurity, and the Australian Cyber Security Centre all base their official post-quantum guidance on the premise that adversaries are currently exfiltrating and storing sensitive, long-lived data. This is because, for any information with a long “shelf-life” (e.g., trade secrets, intellectual property, sensitive personal data, M&A plans, or state secrets), the relevant vulnerability does not occur at a future date when a quantum computer comes online. That vulnerability exists today, when valuable, long-life data is exfiltrated.
This reality reframes quantum risk from a future technological challenge into an immediate IT and data governance and legal compliance issue that requires leadership attention.
What is quantum computing?
With the rapid increase of quantum computing capabilities in the past few years, quantum technologies are gaining global attention. In particular, the United Nations General Assembly declared 2025 as the International Year of Quantum Science and Technology.
Quantum computing systems exploit principles of quantum physics to leverage so-called “qubits”, which are different from binary bits that are either 0 or 1. These qubits can be in a so-called “superposition” of 0 and 1 at the same time, and also be entangled with one another. This allows quantum computers to represent and manipulate many possible states in parallel. For certain specialised problems, such as factoring large numbers, or searching large databases, this parallelism may allow quantum computers to find solutions significantly faster than computers using conventional bits. A cryptographically relevant quantum computer could thereby run algorithms that efficiently break widely used public-key encryption schemes that are currently secure against classical computers.
The shifting legal standard: redefining “state of the art”
Organisations are bound by a dynamic obligation to implement “appropriate”, “adequate”, or “state of the art” security measures across the digital regulatory landscape. These benchmarks evolve in line with technological progress and the emergence of new threats.
In the face of quantum computing, however, legal standards are shifting definitively. For instance, the benchmark for “state of the art” is being redefined in real-time by the U.S. National Institute of Standards and Technology (NIST):
- In August 2024, NIST finalized its first set of post-quantum cryptography standards (FIPS 203, 204, and 205), providing a concrete, accessible and secure alternative to algorithms vulnerable to quantum computing.
- This NIST initiative has become the de facto “global gold standard”. Allied agencies, including regulators in Canada, the UK and Germany, all explicitly reference and align their national guidance with these NIST standards.
- Therefore, a regulator or court may assess an organisation's security measures against this available, finalised, and globally endorsed benchmark. Data protection and cybersecurity laws already require security measures that are “appropriate” to the “state of the art”. In fact, the UK's Information Commissioner’s Office noted in 2024 that organizations should already be identifying and addressing quantum risks.
Quantum risks are most acute for regulated industries. For example, in the EU, the Digital Operational Resilience Act (DORA) establishes specific obligations for managing information and communication technology risk in the financial sector, while the NIS2 Directive does the same for critical infrastructure and the Cyber Resilience Act (CRA) for certain technology manufacturers. In the event of non-compliance, these obligations create a dual threat: significant regulatory scrutiny, which can lead to substantial fines, and civil litigation from customers for contractual breaches or individuals for data protection violations.
The global roadmap: why the time to plan is now
This shift is not occurring in a vacuum. Recognising the challenge of migrating to post-quantum cryptography, agencies across the world have begun publishing multi-year roadmaps (e.g., in Canada, UK and EU). These timelines move the quantum threat to the immediate, setting regulatory expectations for preparedness today. The consensus seems clear: planning, discovery, and inventory must be completed within the next two to four years. The path forward, endorsed by major cybersecurity agencies, sets out a three-phase governance framework.
Phase 1: Understand your quantum risk
This first step involves two key actions: a cryptographic inventory and a data-centric risk assessment. This directly aligns with the mandates from the U.S. Department of Homeland Security to take an inventory of the most sensitive and critical datasets and of all cryptographic systems.
The critical question is which data assets would cause significant harm if decrypted in 10 years’ time. This allows businesses to prioritise the most sensitive, long-life data for migration. These may include core intellectual property, trade secrets, patient data, R&D assets, and proprietary AI models, among others.
Phase 2: Develop a strategic transition plan
Once the risks have been clearly identified, businesses can develop a strategic transition plan. A core objective of this plan should be to achieve “crypto agility”. This is a key technical and governance concept, defined by NIST as the capabilities needed to replace and adapt cryptographic algorithms ... without interrupting the flow of a running system”.
The plan must also integrate post-quantum cryptography into legal and commercial due diligence. Failure to have a quantum-readiness plan may represent a significant liability for a company.
Phase 3: Execute a phased transition
Execution is a long-term process that begins with supply chain diligence. Engaging with vendors is a central risk management exercise, recommended by various regulators as part of any transition plan. An organisation's quantum resilience is only as strong as that of its key technology vendors, cloud providers, and software suppliers.
This could be followed by piloting post-quantum cryptography solutions, which often use a hybrid approach combining classical and post-quantum algorithms, while continuously monitoring the finalisation of NIST standards and guidance from relevant regulatory bodies worldwide.
Conclusion
The quantum era is approaching. By treating the transition to post-quantum cryptography as a strategic imperative now, organisations can safeguard their most valuable data, remain ahead of evolving legal standards of care, and mitigate significant future legal, financial, and reputational risks.
In this first blog in our quantum series, we have outlined the strategic landscape. In our next blog posts, we will explore the specific impacts of the quantum revolution on key business risks and opportunities, including those relating to supply chains, intellectual property, and corporate transactions.
