Quantum computing threats are a governance problem before they are a technical one. This playbook sets out what CISOs should do now, from ownership and discovery to suppliers, budget and board reporting.
How should CISOs prepare their organisation for quantum computing threats? Treat post-quantum migration as a multi-year programme with a named owner, a budget and dated milestones, rather than as a technology problem for later. The cryptography most exposed to a future quantum computer is public-key cryptography such as RSA, ECDH and ECDSA, and it sits inside almost every system you run, from websites and VPNs to signing services, payment links and digital asset custody.
This playbook sets out what the main standards bodies and cyber agencies are asking organisations to do, and how a CISO can turn that guidance into a programme the board can follow.
Why quantum computing threats are a CISO problem now
Nobody can give you a firm date for a cryptographically relevant quantum computer. The case for acting now rests on two other facts. First, encrypted data can be recorded today and decrypted later, the attack known as harvest now, decrypt later. Second, migration takes years. CISA, the NSA and NIST jointly urge organisations “to begin preparing now by creating quantum-readiness roadmaps, conducting inventories, applying risk assessments and analysis, and engaging vendors”.
The planning dates are already set:
The UK NCSC asks organisations to define migration goals, carry out discovery and build an initial plan by 2028, complete their highest-priority migrations by 2031 and complete migration by 2035.
The EU coordinated implementation roadmap says high-risk use cases should move to post-quantum cryptography as soon as possible and no later than the end of 2030, with the transition completed for as many systems as practically feasible by 2035.
NIST notes that Executive Order 14412 requires US federal high-value assets and high-impact systems to migrate by 2030 for key establishment and by 2031 for digital signatures, and that many organisations working with the federal government will be affected.
The G7 Cyber Expert Group points to 2035 as an overall target and suggests addressing the most critical financial sector systems in the 2030 to 2032 period.
The NCSC describes migration as a mass technology change that will take a number of years, and older systems often hide cryptography that has built up in haphazard ways. The 2028 milestone for discovery and an initial plan leaves little room for a slow start.
A practical playbook for CISOs
Name an owner and stand up a programme. The CISA, NSA and NIST factsheet recommends starting with a project management team to plan and scope the migration, including cyber security and privacy risk managers who can prioritise the assets most at risk. The G7 roadmap lists executive-level risk awareness and defined key roles as the first outcome. In practice that means an accountable executive, a programme lead and named contacts in architecture, procurement, risk and each business line.
Set migration goals tied to business risk. The NCSC asks organisations to decide what they want the migration to achieve, take account of regulatory requirements and treat the work as part of wider cyber resilience. It also suggests using the migration to retire or simplify systems where that makes sense.
Run discovery across the whole estate. You cannot prioritise what you cannot see. CISA, the NSA and NIST recommend discovery tools for network protocols, end-user systems and servers, and the code and dependencies in your CI/CD pipeline, and warn that tools may miss cryptography embedded inside products, so ask vendors for lists. The NCSC reminds organisations that managed service providers may deliver most of their IT capability, so they belong in scope. If your organisation holds or settles digital assets, include the signing keys and custody systems too, because they rely on the same public-key algorithms.
Prioritise by data lifetime, exposure and effort. The EU roadmap treats a use case as high-risk if a loss of confidentiality after 10 years or more would still cause significant damage. The Europol Quantum Safe Financial Forum framework weighs data sensitivity and lifespan, exposure to attackers and business impact against solution availability, cost and third-party dependencies. That gives you a defensible order of work rather than a list of everything at once.
Bring suppliers into the plan early. Much of your exposure sits in products you buy. CISA, the NSA and NIST encourage organisations to ask vendors for their post-quantum roadmaps and to plan contract changes so that new products arrive with post-quantum cryptography built in and older products are upgraded in time. The NCSC suggests sharing a statement of intent with suppliers, and its 2028 milestone includes telling suppliers what you need.
Budget beyond a single leadership cycle. The NCSC is explicit that migration “will typically involve activity that spans multiple leadership cycles in most large organisations” and that organisations should budget for preparatory activities as well as the migration itself. Ring-fence funding for discovery and planning now, and link larger spend to existing technology refresh cycles where you can.
Choose a route for each system and build in agility. The NCSC describes several options: migrate in place, re-platform, retire the service, run it to end of life or, in limited cases, tolerate the risk. NIST published its first post-quantum standards, FIPS 203, 204 and 205, in August 2024. Prefer standardised, tested implementations from your suppliers, and design systems so that algorithms can be changed again without a rebuild.
Measure progress and test it. Track discovery coverage, the share of priority systems migrated and, as the NCSC suggests, how many clients actually negotiate post-quantum algorithms. The NCSC also advises setting the criteria you will use to decide when to end support for traditional algorithms, because you are only fully protected once nothing depends solely on them. The G7 roadmap ends with testing, validation and ongoing monitoring for the same reason.
What to report to the board
Boards do not need the mathematics. They need to know who owns the programme, what has been found, what will be fixed first and what it will cost. A useful quarterly report covers:
the accountable owner and the programme plan against the 2028, 2030 to 2031 and 2035 milestones that apply to you
discovery coverage, including third parties and managed service providers
the highest-priority systems, ranked by data lifetime, exposure and business impact
supplier readiness and the contract changes in progress
budget used and forecast, and any risks the organisation has chosen to tolerate
The G7 roadmap asks for sustained executive engagement and for post-quantum work to sit inside existing governance and risk management frameworks. Reporting through the same risk committee that oversees other cyber risks is usually the simplest way to do that.
Notes for regulated sectors
Financial services. The NCSC expects many banking and financial services organisations to focus on migration earlier, in line with global partners in the sector. The Europol report highlights no-regret actions that can start now, such as hybrid post-quantum encryption for public-facing websites and removing weak or outdated cryptography that adds technical debt.
Aerospace and defence. Long-lived hardware is the hard part. The NCSC says the 2028 plan should identify any need to migrate long-lived hardware roots of trust, and suppliers to national security systems also need to track NSA CNSA 2.0 dates. We keep these milestones, with links to each primary source, on our regulatory clock.
Public services and critical infrastructure. The NCSC guidance is written for cyber security professionals, large organisations and the public sector. Where you run operational technology or extensive physical infrastructure, it advises planning any changes to coincide with other infrastructure maintenance and improvements. Bodies that supply or connect to US federal systems should read the NIST guidance on Executive Order 14412 closely.
Where QuantSec fits
The early stages of a programme are mostly discovery and prioritisation, and that is where QuantSec helps. Our vulnerability mode scans on-chain and off-chain code, infrastructure and dependencies for quantum-vulnerable cryptography and ranks each finding by severity and exposure. Our compliance mode maps in-scope cryptography against the framework you select. Both produce a digitally signed quantum security report with a prioritised migration plan that you can take to your board, auditors and suppliers. Anyone can check that a report has not been altered, because its digital signature must match its content.
For complex estates, our enterprise and institutions approaches cover mixed modern and legacy systems, and our quantum migration as a service team can carry out the migration with you.
Sources
CISA, NSA and NIST: Quantum-Readiness: Migration to Post-Quantum Cryptography
NIST: NIST report provides guidelines for transition to post-quantum cryptography (October 2026)
NIST: NIST releases first 3 finalized post-quantum encryption standards (August 2024)
Europol: Prioritising post-quantum cryptography migration activities in financial services
Get your quantum readiness programme started
QuantSec scans your on-chain and off-chain systems for cryptography a quantum computer could break, then delivers a digitally signed report with a prioritised migration plan your board can act on. When you are ready to act, our team can carry out the post-quantum migration with you.
