Last Thursday, IonQ, the American quantum computing company, reported the best quarter in its history: $173.8 million in revenue, up 336% on a year earlier. Almost half of it came from a chip foundry IonQ had just finished buying. Then the chief executive named "one of our customers' most urgent needs today". It was cybersecurity, and IonQ sells post-quantum encryption. As I read the release, the quantum industry's most urgent product is protection from quantum computers.
That small irony holds most of what a CEO needs to know about quantum. The computers still do little for most businesses. The risk they pose to your encryption is already here, because anything copied today can be read once they arrive. So my advice is to leave quantum computing on the watch list for a few more years and to start on quantum security this quarter.
Nobody can break today's encryption with a quantum computer yet, but the estimates of what it would take keep shrinking. In 2019, Google's Craig Gidney and a co-author put the bill for cracking RSA-2048, one of the locks on the internet, at 20 million qubits. Last year he brought it under a million. This spring a start-up called Oratomic sketched an attack on the elliptic-curve keys used across the web with about 10,000 atoms, although at that size its own figures have a single key taking the best part of a year or more. None of these machines exists. Google set itself 2029 to finish its own switch anyway. Gidney, who does not expect a big enough machine by 2030, gave the reason: he prefers "security to not be contingent on progress being slow."
The risk has a name: harvest now, decrypt later. Someone copies your encrypted traffic today, stores it cheaply and reads it when the computer exists. The European Commission says such attacks are "already likely occurring". Michele Mosca, who runs the quantum-security firm evolutionQ, reduced the question to a sum: how long your data must stay secret, plus how long your migration takes. If the total runs past the machine's arrival, you are late already. His firm's latest survey for the Global Risk Institute puts the odds of a code-breaking machine within ten years at 28% to 49%. A merger file or a patient record that must stay private until 2036 already sits inside that window.
Europe has put dates on it. The roadmap EU member states adopted in June 2025 asks each government to start its transition by 31 December this year, seven weeks from now, and to finish for high-risk uses by the end of 2030. High-risk means data whose exposure would still hurt in ten years. Germany published its national timeline last month. NIST, the American standards body, will deprecate the old algorithms after 2030 and disallow them after 2035. The roadmap is written for governments, but as I read it, companies will meet it through their regulators, critical-infrastructure rules and their largest customers' procurement forms. Meanwhile the Commission is due to propose a Quantum Act this month, and a senior official described the draft to POLITICO with a sentence Brussels has rarely said out loud: "There's nothing to regulate." After the AI Act, that counts as character development.
Most companies know all this and are waiting. Bain, which sells help with exactly this problem, found in February that 70% of IT and security leaders expect the risk within five years. Only 9% have a defined roadmap, and nearly three quarters are waiting for their vendors to sort it out.
The fix is mostly unglamorous software. Post-quantum algorithms run on ordinary computers, and more than 65% of the human traffic reaching Cloudflare already uses them because browsers and networks switched them on by default. The hard part is finding the old cryptography in your own estate: the payment links, the code-signing keys, the supplier connection from 2014 that nobody dares to touch. Cloudflare, a vendor with its own shop to fill, recommends making post-quantum support a requirement in every purchase. That one clause turns each renewal into a small inventory, with the supplier doing the counting.
Some vendors offer a more exotic cure: quantum key distribution, specialist hardware that uses physics to exchange keys. Britain's National Cyber Security Centre does not endorse it for government or military use and calls quantum-safe cryptography "the best mitigation". So when a quantum company tells you its most urgent product is protection from quantum computers, believe the urgency and shop carefully for the product.
Somewhere, on storage your company will never see, a copy of this year's board pack may already be sitting, encrypted and patient, waiting for a computer nobody has built.
If someone in your company signs off security budgets, send them this one. And if it was forwarded to you, you can subscribe at vanguards.media.
David
Sources: IonQ, Q3 2026 results release, 5 Nov 2026. Gidney and Ekerå, How to factor 2048 bit RSA integers in 8 hours using 20 million noisy qubits, Quantum, 2019; Gidney, How to factor 2048 bit RSA integers with less than a million noisy qubits, arXiv, 2025. Cain et al. (Oratomic and Caltech), Shor's algorithm is possible with as few as 10,000 reconfigurable atomic qubits, arXiv, 2026. Google, Quantum frontiers may be closer than they appear, 25 Mar 2026. European Commission, Post-Quantum Cryptography policy page; NIS Cooperation Group, A Coordinated Implementation Roadmap for the Transition to Post-Quantum Cryptography, 23 Jun 2025. BMDS, BMI and BSI, Nationale Umsetzung der EU-Roadmap zur Umstellung auf Post-Quanten-Kryptografie (national implementation of the EU roadmap), 12 Oct 2026. NIST IR 8547, Transition to Post-Quantum Cryptography Standards, Oct 2026. Mosca and Piani, Quantum Threat Timeline Report 2025 (Global Risk Institute and evolutionQ), exec summary Mar 2026. Bain & Company, Execs Aren't Prepared for the Post-Quantum Cybersecurity Risks They Know Are Coming, 18 Feb 2026. Cloudflare, Cloudflare targets 2029 for full post-quantum security, 7 Apr 2026. NCSC, Quantum security technologies. POLITICO Europe, Forget AI, Europe has a plan to win the next tech revolution, 31 Oct 2026.