Where to start a post-quantum migration
Do not claim a migration before you can list what has to move.
What can go wrong
A roadmap with no inventory does not say what has to move. One project that treats key establishment and signatures as the same job hides two different pieces of work.
A stronger practice
The CISA, NSA, and NIST fact sheet, as of 17 August 2023, says begin with a quantum-readiness roadmap, an inventory of quantum-vulnerable cryptography, a risk assessment, and vendor engagement.
The PQC Migration Handbook (AIVD, CWI, and TNO, December 2024) calls the first step a quantum-vulnerability diagnosis and gives its concrete steps to urgent adopters, organisations that need to start because they cannot afford to delay. Regular adopters, in that handbook, do not need to react yet.
Handbook guidance: if you are not sure which you are, read Keep software updated and then Priority.
What to ask
What data or keys must stay good for a long time, and who owns the stack?
Evidence
An inventory record, not a slogan.
A weak answer
"We are quantum safe."
A stronger answer
"We have a first inventory, a reason the top items are first, and a date for the next pass."
Which pass
This is the first pass.
Options
The choice for a listed system is on Choosing an option. This page does not make that choice.
The Dutch handbook advises against relying on the security of quantum key distribution for the time being.
Sources
- CISA, NSA, and NIST, Quantum-Readiness fact sheet, as of 17 August 2023. Fact sheet
- AIVD, CWI, and TNO, The PQC Migration Handbook, December 2024. Handbook