Quantum computers and Q-Day: challenging military dominance.
Q-Day in the 2030s could break public key cryptography. China is mobilizing 1 trillion yuan for quantum computing; the US is shifting to post-quantum encryption before 2035.
Quantum computing is emerging as a factor that could reshape global military dominance. "Q-Day"—the point at which quantum capabilities break current encryption systems—is predicted for the 2030s. As China accelerates investment and the US sets a 2035 deadline for transitioning to post-quantum encryption, the technology race is shifting from aircraft carriers and fighter jets to qubits and algorithms.
The debate in Japan's parliament between Prime Minister Sanae Takaichi and an opposition politician regarding emergency situations with Taiwan (China) highlighted the sensitivity of the situation, but analysts warn the core threat may come from quantum computing capabilities.
Quantum threat: from theory to reality
Jesse Van Griensven (University of Waterloo, CEO of EigenQ) describes the scale of the risk with a comparison: with current computers, a hacker can access personal accounts; with quantum computers, "the entire bank's money is gone." Such machines could disable airports, power plants, telecommunications networks, and military forces, sending the United States "back to the Stone Age" without firing a single bullet.
Popular encryption systems like RSA (Rivest–Shamir–Adleman, 1977) are based on problems that classical supercomputers took centuries to solve. A sufficiently powerful quantum computer could reduce this to a few days or weeks. This is not just a difference in speed, but a leap in the very nature of computing power.
Investment and deployment: China accelerates.
In March, Zheng Shanjie, head of China's state planning agency, announced plans to establish a government-backed fund to raise 1 trillion yuan ($140 billion) for "hard technology," including semiconductors, renewable energy, and quantum computing.
Morgan Peirce (Center for New American Security) argues that China is funding quantum communications on a much larger scale than the US or anywhere else, particularly in the distribution of quantum keys. Beijing has built a massive quantum communications infrastructure, with networks spanning thousands of kilometers between cities and facilities.
The strategy: "Harvest now, decode later."
Ryan Fedasiuk (American Enterprise Institute) notes that quantum technology is not yet mature and is not a "magic switch" to shut down the grid or infiltrate immediately. The greater risk lies in the current strategy of stockpiling encrypted data to await decryption when quantum capabilities mature. At that point, sensitive data repositories stolen in the past – previously thought secure – could be exposed, impacting military and intelligence operations.
According to Fedasiuk, if China possesses quantum computers capable of correcting errors before the US, Japan, or Taiwan can switch to quantum-resistant algorithms, Beijing could gain an asymmetrical advantage in intelligence: reading sensitive traffic and compromising systems previously considered secure.
Military consequences and the need for transformation.
The shift to quantum-resistant encryption is critical for the military. In a conflict scenario, a party capable of deciphering enemy communications in real time could gain insight into the enemy's positions, plans, and weaknesses. Analyses warn that if the U.S. or the Japan Self-Defense Forces haven't completed the transition, while China possesses cryptographically relevant quantum computers, the risk of interference with aircraft carriers, UAVs, and misdirection is real.
In 2022, former US President Joe Biden issued a memorandum requiring federal agencies to transition to quantum-resistant algorithms by 2035. Peirce stated that the US government estimates that quantum computers capable of breaking today's public key cryptography could appear by 2035, possibly even sooner according to some analyses. The scale of this transition is enormous, requiring widespread system updates and rigorous security testing.
Strategic surprise and response window
Lindsay Gorman (Marshall Foundation Germany) argues that universal fault tolerance quantum computing could be a rare "winner-take-all" field. To achieve devastating impact, competitors need to keep their capabilities secret and launch them at the right time. As soon as there are signs that either side is nearing the finish line, emergency programs switching to post-quantum encryption will be activated. According to her, a worst-case scenario can be avoided if the transition begins immediately.
Key military applications of quantum computers
| Field | Impact by source |
|---|---|
| Cryptography | The Shor algorithm can break RSA and ECC; advancing the development of post-quantum cryptography to protect highly confidential communications and data. |
| Military optimization | Solve resource allocation, logistics, and routing problems; optimize the allocation of aircraft, warships, troops, and supply lines. |
| Materials, weapons, sensors | Molecular/atomic simulation is used to design ultra-durable materials, high-energy weapons (e.g., military lasers), and superior sensors. |
| Military AI | Accelerate and improve the accuracy of decision-making systems, satellite imagery analysis, and target identification. |
Strategic focus
- Investment: China is mobilizing 1 trillion yuan (US$140 billion) for "hard technology," including quantum technology.
- Defense: The US aims to transition its federal system to post-quantum encryption by 2035.
- Infrastructure: Quantum communication and quantum key distribution are being deployed on a large scale in China.
- Retrospective risk: The "harvest now, decrypt later" strategy means that past data may be exposed in the future.
The quantum race is not just about science – it's about power and national security. The party that achieves cryptographically relevant quantum computing first may gain a significant strategic advantage; however, the actual impact depends on the speed and extent to which nations transition to quantum-resistant systems.
