You’d better mind your PQC Ps and Qs.
After AI, quantum computing will likely be the next big thing in tech. And just like AI, quantum computing already has its own doomsday scenario. In quantum’s Hollywood movie nightmare, a computer can do ridiculously complex computations in seconds that would take a classical computer thousands of years. The computer uses this superpower to brute force encryption keys generated using the de facto RSA algorithm. That gets it into your Bitcoin wallet, your enterprise backups, and sensitive messaging apps that were previously encrypted from end to end. It also gets into everyone else’s.
This hasn’t happened yet, but mathematician Peter Shor laid the groundwork for it in 1994 when he invented an algorithm that could theoretically crack RSA using a quantum computer. Since then, people have been trying to build one. The problem is creating enough qbits (a quantum version of a regular binary computer bit) to do the math. Qbits are fragile, so developing such a machine, which we call a cryptographically relevant quantum computer or CRQC, is a tough problem but people are working on it.
The NIST IR 8547 draft on the topic says that CRQCs don’t exist yet. Not that a nation state would necessarily let on if it had one.
Anyway, it’s coming sooner or later. The Cloud Security Alliance cites a consensus estimate for a cryptographically relevant quantum computer by 2035 at the outside.
So, shouldn’t the world be getting ready to avoid having all of its secrets revealed? Older readers will remember the panic in 1999 as people realized that the year 2000 could break the world’s computers thanks to a software bug that made old computers incompatible with the new millennium. Engineers worked frantically to mitigate the problem and succeeded well enough so that laypeople could crow about how the whole thing was blown out of proportion. Now governments on both sides of the Atlantic believe we should be making similar preparations for the quantum era.
Luckily for us, mathematicians have already created encryption algorithms that will be immune to quantum computation. These fall under the umbrella of post-quantum cryptography (PQC), and they will save us, but only if we all start using them. The UK’s National Cyber Security Center has already proposed key dates for the move to PQC, while in the US the Treasury Department has announced its own initiative.
The 2035 Deadline Starts Now
The first major milestone on the NCSC’s proposed timeline falls in 2028, with instructions for organizations to define their migration goals and conduct a full discovery exercise for data that should be re-encrypted using PQC. It recommends that organizations execute the higher-priority migrations by 2031, with a view to migrating the rest by 2035.
The Treasury Department’s announcement of its Quantum-Readiness Task Force follows the White House’s Executive Order 14412 in June 2026: “Securing the Nation Against Advanced Cryptographic Attacks”. It focuses on helping the financial sector in particular transition to PQC.
These efforts have appeared now for at least three reasons:
First, no one really knows when CRQCs might arrive. 2035 is a guess, and we’re notoriously bad at predicting the future.
Second, building new algorithms into products takes years, especially cryptographic ones, which are extremely complex (hence the old warning for developers: “never roll your own cryptographic algorithms”. So, a deadline nine years hence only works if you begin discovery now.
Third, that deadline has technically already passed. A concept known as harvest now, decrypt later (HNDL) puts all today’s data at risk. Malicious actors who steal that data today would be able to sit on it and decrypt it once quantum computing allows it. That is a problem for long-lived data records. A Europol analysis of this threat places policy makers and government at particularly high risk for HNDL. Citizens and private individuals are at low to medium risk, but high net-worth individuals who are worth the quantum computing time still make sensitive targets.
So, data exposure depends in part not just on how long someone takes to string enough qubits together to make Shor’s algorithm work, but on the longevity of that data. To truly understand how susceptible they are to HNDL, organizations must therefore have a record of their long-lived data inventory. The NCSC’s discovery phase already calls for a record of the data organizations hold, including its expected lifetime and its value to an adversary.
Technology’s Barely the Half of It
While PQC is a very technical pursuit, it’s also a process-centric one. Multiple encryption algorithms will have to pass muster against different quantum algorithms, but the likes of NIST are already well ahead of the curve there.
The real problems are always organizational rather than technical. No amount of technical wizardry will help to protect your data unless you know which assets need migrating, who supplies them, and who owns them in your organization. This is squarely an information security management system challenge.
The bottleneck here is visibility rather than algorithm choice. According to an Entrust/Ponemon 2026 global survey, only 43% of organizations report full or complete visibility of the cryptographic estate. That same survey found only 26% with a fully implemented crypto agility strategy. Another 31% had partially implemented it, the report found. The White House has also wagged its finger at industry, calling approaches to discovery and management of cryptography “often insufficient”.
Your Cryptographic Future is Buried in Your Suppliers’ Software
Another complicating factor as companies grapple with the quantum cryptography challenge is that much of the cryptography is embedded in vendor products. The NCSC points out that customers’ plans will evolve in step with their suppliers’ roadmaps. In the US, the Treasury Department has given this issue its own “third party and vendor readiness” work stream.
Given the risks involved, it makes sense to quiz suppliers about their intentions here. The IO State of Information Security Report 2025 found that 61% of respondents had a supplier-caused incident in the prior year. While today such incidents often come down to software bugs or human error, we don’t want inadequate PQC compounding the problem, so vendors should be able to provide concrete PQC readiness dates to help customers plan testing and procurement.
Why PQC Readiness Belongs Inside an ISO 27001 ISMS
The NCSC points out that most migration work to PQC is already good cybersecurity practice, pointing to activities including asset management, building a clear view into systems and services, and being intentional about how you manage your supply chains. These are all practices that ISO 27001 helps organizations to meet. A statement from the G7 Cyber Expert Group on coordinated transitions to PQC in the financial sector also points to ISO 27001 as a pivotal standard.
ISO 27001 has everything that you’d want to support your crypto-agility initiative with. Organizations wanting to get ahead of the PQC challenge should consider ownership first by appointing a named senior sponsor. Both the NCSC and the US Executive Order advise this. ISO 27001 clause 5.3 also advises assigning information roles and responsibilities.
Inventory and classification are also key tenets of ISO 27001. And organizations should consider extending A.5.9 and A.5.12 to cryptographic dependencies and data lifetime.
Supplier controls A.5.19-24 also carry vendor roadmap requests into agreements and reviews. Use these as your guidance for asking for readiness dates and monitoring supplier migration plans.
All of these are relevant, but ISO 27001 also has a specific home for policies around the use of cryptography: A.8.24.
There’s no shortage of best-practice information for leveling up your cryptography game, and other than yesterday, there’s no better time to start implementing it than now. Quantum science deals with things that are very, very small, but it’s amazing how big and important small things get as you approach them.
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