Building a practical path to post-quantum cryptography

A natural evolution, not a cliff edge

The "quantum threat" narrative often swings between two extremes: imminent catastrophe or distant irrelevance. The reality occupies a more pragmatic middle ground. Quantum computers are highly specialized accelerators that exploit quantum physics to solve specific hard problems. They have the potential to crack modern encryption, but they will not replace classic servers overnight, nor will they instantly break every encryption protocol on the internet. What they will do is gradually shift the security landscape, much as previous cryptographic transitions have done over the past three decades.

In late 2024, the Global Risk Institute, a Toronto-based financial services think tank, surveyed 32 quantum computing experts on when a quantum computer could break a 2048-bit RSA key within 24 hours. An average of optimistic and pessimistic estimates from the experts gave it an even 50-50 probability of reaching this code-breaking milestone by 2040. This timeline, uncertain but measurable, creates space for deliberate planning rather than emergency reaction. The near-term focus should be on "harvest now, decrypt later" scenarios, where adversaries collect encrypted data today and then hold it for future decryption later when that capability becomes possible. This is particularly applicable for information requiring confidentiality beyond 10 years.