Quantum computing use cases in defense
Quantum technology could apply in defense in four groups: sensing, navigation and detection without satellite signals; cryptography; secure communications; and quantum computing. As of Q4 2026 the public record is government programs, awards, strategies and a few trials, with little performance data, and most operational detail is not public.
Updated Q4 2026
Where quantum technology could apply in defense
Public government sources point to four groups: sensing, navigation and detection that do not rely on satellite signals; cryptography; secure communications; and quantum computing. The sources are program pages, procurement and award announcements, strategies and a small number of trials. They describe plans and awards far more often than measured results, and the evidence levels below say which is which.
| Use case | Best public evidence | Evidence level |
|---|---|---|
| Sensing, navigation and detection | US Defense Innovation Unit Transition of Quantum Sensing program (field testing from 2025); UK flight test of an optical clock and quantum inertial elements (2024); NATO quantum strategy (2024) | Program and flight test; no results published |
| Cryptographic risk and migration | US National Security Memorandum 10 (2022); NIST IR 8547 (2026); UK NCSC timelines (2025) | Policy deadlines |
| Secure communications | NATO quantum strategy (2024); UK NCSC position on quantum key distribution (2025) | Strategy and policy position |
| Quantum computing | DARPA Quantum Benchmarking Initiative (stage status to October 2026) | Verification program; no defense application results |
Sensing, navigation and detection: programs and one flight test
The most concrete public activity is in sensing. In March 2025 the US Defense Innovation Unit (DIU) announced that field testing was starting under its Transition of Quantum Sensing (TQS) program. The program began in summer 2024 and aims to demonstrate the military utility of quantum sensors for positioning, navigation and timing and for anomaly detection. It has five lines of effort: quantum inertial sensors, gravimeters, magnetic anomaly detection, magnetic navigation, and components such as chip-scale lasers. DIU named 18 companies, among them Honeywell, Lockheed Martin, Northrop Grumman and Q-CTRL, and planned more than 10 field tests across ground, air and maritime domains in the initial phase, which spans roughly 12 months. The release says significant progress is expected through 2025 and reports no measured results.
In July 2025 Honeywell said it had been selected for the program under two contracts: CRUISE, for inertial measurement units based on quantum sensors, and QUEST, for magnetic navigation. The release describes aims and not test outcomes.
In the UK, a flight on May 9, 2024 carried the Tiqker optical atomic clock and a cold-atom system, intended for a quantum inertial navigation system, on QinetiQ’s RJ100 demonstrator at MoD Boscombe Down. Infleqtion led with BAE Systems and QinetiQ, and the government funded nearly £8 million. The government release calls it a milestone toward the national mission of quantum navigation systems on aircraft by 2030. It states that the systems cannot be jammed or spoofed and gives no accuracy figures or test conditions. The UK Strategic Defence Review 2025 lists quantum among the technologies redefining warfare and says quantum technologies have the potential to reduce dependence on satellite GPS, which may be vulnerable to interference. The NATO strategy summary adds sensing, imaging and improved detection of submarines to the list of defense uses. A company-run airborne navigation trial is covered in the transport guide.
Cryptography: where defense organizations already have dates
US National Security Memorandum 10, issued in May 2022, sets a goal of mitigating as much of the quantum risk to cryptographic systems as is feasible by 2035. NIST’s final IR 8547 (October 2026) says NIST will deprecate quantum-vulnerable public-key cryptography after 2030 and disallow it under NIST standards after 2035. Executive Order 14412 (June 22, 2026) and OMB Memorandum M-26-15 (June 24, 2026) require high-value assets and high-impact federal systems to adopt post-quantum key establishment by December 31, 2030 and post-quantum digital signatures by December 31, 2031. The UK NCSC asks large organizations and operators of critical national infrastructure to define migration goals by 2028, finish the highest-priority migration by 2031 and complete it by 2035. The UK Strategic Defence Review says advances in quantum computing offer the potential to break encryption, which would make secure communications much harder.
Secure communications: NATO’s strategy and a UK position against quantum key distribution
NATO’s foreign ministers approved its first quantum strategy on November 28, 2023, and NATO released a summary on January 17, 2024. The stated aim is a “quantum-ready” Alliance. The summary lists securing data communications with quantum-resistant cryptography among the defense uses, and notes that six of the 44 companies selected to join its DIANA accelerator program specialize in quantum technology.
Quantum key distribution is a different matter. In August 2025 the NCSC wrote that it will not support the use of quantum key distribution for government or military applications, that it recommends post-quantum cryptography as the primary mitigation, and that quantum key distribution does not provide authentication. The paper also says combining quantum and classical components makes systems harder to secure. Other agencies may take different positions.
Quantum computing: DARPA tests the machines, not the applications
DARPA’s Quantum Benchmarking Initiative seeks to determine whether an industrially useful quantum computer can be built by 2033, meaning one whose computational value exceeds its cost. Stage A awards go up to $1 million, Stage B up to $15 million and Stage C up to $300 million. DARPA’s page, current as of Q4 2026, lists two companies in Stage A (Google Quantum AI and Quandela), seven in Stage B and six in Stage C: Atom Computing, Diraq, IBM, IonQ, Microsoft and PsiQuantum. DARPA says it has evaluated more than 20 organizations since mid-2024, and the November 2025 Stage B selection named 11 companies. DARPA estimates that it is more likely than not that at least one company will build an industrially useful quantum computer by 2033, and says that multiple, a single or even no participants will show a path to an industrially useful machine. A solicitation for new Stage A entrants, published on March 9, 2026, closes on November 30, 2026.
The program verifies hardware roadmaps. It does not publish defense application results, such as an optimization or simulation job run for a military customer.
What is not public
Public pages cannot show most of what a defense buyer would need to judge a quantum use case. Public sources do not include:
- Results from the DIU field tests. The release gives plans and company names, not outcomes.
- Accuracy figures and test conditions for the UK flight trial, and any test of resistance to jamming or spoofing beyond the statement that the systems cannot be jammed or spoofed.
- Any defense application run on the machines in the DARPA program.
- Contract values for most awards. The DIU release lists companies and no amounts.
The UK Department for Transport study, in its section on implementation costs, notes that quantitative information tends to be classified. A claim with no public test conditions is unverified, whoever makes it.
What the value estimates say, and what they do not
The McKinsey Quantum Technology Monitor, April 2026, gives defense no dollar value of its own. It rates aerospace and defense as medium economic value for quantum computing in 2025 to 2030 and high in 2030 to 2035. For quantum sensing it projects a worldwide market of about $2.8 billion to $3.1 billion in 2025 and $7.1 billion to $10.1 billion in 2035 across all customers, in a conservative and an optimistic case. It cites GPS-denied navigation and subsea exploration as fueling defense-led adoption in one sensor segment. The range is an order of magnitude for the sensing market and not a forecast of defense spending.
How to read a quantum defense claim
- Is it an award or a result? The DIU and Honeywell announcements list contracts and aims. Neither reports a test outcome.
- Who states the claim? “Cannot be jammed or spoofed” is the government release’s statement, with no test conditions attached. Ask for them.
- Does the program test an application? DARPA’s program verifies machine roadmaps. It says nothing yet about military use cases.
- What does the baseline cost? Navigation claims should compare with inertial and other classical backup systems, not only with satellite navigation.
- Do agencies agree? The NCSC will not support quantum key distribution for military use. NATO’s strategy lists quantum-resistant cryptography, which is a different technology.
- What is missing? Classified work is not public, so a gap in the public record does not mean no work exists.
What a defense organization or supplier can do now
- Build a cryptographic inventory and map it to the dated steps: 2028, 2031 and 2035 for the NCSC, 2030 and 2035 in NIST IR 8547, and 2035 in NSM-10; the most sensitive US federal systems have earlier dates, December 31, 2030 for key establishment and December 31, 2031 for signatures.
- List the systems that depend on satellite positioning and timing, and test classical backups before judging quantum ones.
- Follow public solicitations and field-test announcements, such as DARPA’s open Stage A topic and DIU’s quantum sensing work, and ask any vendor for test conditions behind each claim.
Questions
Is quantum technology used in defense today?
Public sources show programs, awards and field trials, and none says a quantum system is in routine military use. The dated requirements that are in force today concern cryptography, such as the NCSC migration timelines and the goal in NSM-10.
Which quantum technology is closest to military use?
Sensing. The DIU program planned more than 10 field tests in an initial phase of roughly 12 months, and a UK flight test in 2024 carried an optical clock and a cold-atom system. Neither release gives performance figures.
Will quantum computers break military encryption?
The UK Strategic Defence Review 2025 says advances in quantum computing offer the potential to break encryption. NSM-10 asks US agencies to reduce the risk as far as feasible by 2035, and NIST’s IR 8547 says it will disallow quantum-vulnerable public-key cryptography after 2035. DARPA estimates that a useful quantum computer by 2033 is more likely than not, and says no participant may succeed.
Does NATO have a quantum strategy?
Yes. Foreign ministers approved it on November 28, 2023 and NATO published a summary on January 17, 2024. It lists sensing, positioning, navigation and timing, submarine detection and quantum-resistant cryptography among the uses.
How can a defense supplier assess a quantum claim?
Ask for the baseline, the test conditions, who ran the test and whether it was on hardware or in simulation. The Quantum Readiness Check is a short assessment, and TQI Advisory reviews claims against public evidence.
Sources
- DIU’s TQS Field Testing To Begin Across Five Critical Areas, US Defense Innovation Unit, March 12, 2025.
- Honeywell Awarded U.S. Government Contracts to Develop Quantum Sensor-Based Navigation Systems, Honeywell, July 17, 2025.
- Un-jammable quantum tech takes flight to boost UK’s resilience against hostile actors, UK Government press release, May 13, 2024.
- National Quantum Strategy Missions, UK Government (updated December 14, 2023).
- The Strategic Defence Review 2025: Making Britain Safer, secure at home, strong abroad, UK Ministry of Defence, June 2, 2025.
- NATO releases first ever quantum strategy, NATO, January 17, 2024.
- Quantum networking technologies, UK National Cyber Security Centre, August 5, 2025.
- Timelines for migration to post-quantum cryptography, UK National Cyber Security Centre, March 20, 2025.
- National Security Memorandum on Promoting United States Leadership in Quantum Computing While Mitigating Risks to Vulnerable Cryptographic Systems, The White House, May 4, 2022 (archived).
- Transition to Post-Quantum Cryptography Standards, NIST IR 8547, October 27, 2026 (final; the initial public draft of November 12, 2024 is superseded).
- Securing the Nation Against Advanced Cryptographic Attacks, Executive Order 14412, The White House, June 22, 2026.
- Quantum Benchmarking Initiative, DARPA program page (list current as of Q4 2026).
- Stage B selection, DARPA, November 6, 2025.
- Socio-economic impacts of quantum technologies in transport, UK Department for Transport, November 14, 2024 (report PDF, cited for its note on classified cost data).
- McKinsey Quantum Technology Monitor 2026, April 2026 (ratings and sensing market range).
Check a quantum claim against public evidence
TQI Advisory reviews quantum claims against public sources and assesses cryptographic exposure.