[The United States] was ahead for so long, and in so many areas, that it hasn’t really had to do much thinking about what it means to be behind.
- – Physicist Mitch Ambrose, on China’s quantum technology advancements
As the tech Cold War intensifies with China and President Xi Jinping striving to establish the People’s Liberation Army Navy (PLAN) as the dominant maritime power in the Indo-Pacific, the U.S. Navy faces a critical point: Achieve technological superiority for tomorrow’s conflicts or surrender its competitive advantage to China. To visualize what falling behind in the race for technology entails, imagine this fictional news briefing set in the near future:
U.S. intelligence community officials reported this morning that the newly developed Chinese PLAN quantum computers have completed operational testing and have successfully demonstrated their ability to break military-grade encryption in the laboratory environment, severely degrading the confidentiality of top-secret communications across U.S. Navy platforms in the Indo-Pacific. At this afternoon’s press briefing, the U.S. Secretary of Defense (SecDef) stated that the Department of Defense (DoD) is scrambling to partner with federal and civilian industry leaders to secure naval communications against these emerging quantum computing hacks. Analysts at the DoD expect China’s quantum codebreaking systems to be fully deployable within three to five weeks, giving the DoD a very short window of time to devise a solution. This announcement comes just one week after the Chief of Naval Operations (CNO) issued a warning to U.S. Pacific Fleet Submarine Force leaders stating that Chinese Jin-class ballistic missile submarines have completed initial laboratory testing for quantum sensing technology, giving them unparalleled navigational accuracy without cumbersome periodic GPS calibration requirements. The U.S. Navy’s Undersea Warfare Development Center is currently working with submarine force leadership to analyze the increased threat that China’s new undersea quantum sensors pose to submarines operating in the Pacific. In last night’s interview with the SecDef regarding the emerging Chinese quantum threat to national security, he stated, “We’ve been caught off guard, and it’s an all-hands effort as we scramble to figure this out.”
While this narrative may seem like science fiction, China’s quantum computing research and development (R&D) is well underway, and the global race for quantum superiority has begun. This disruptive technology will transform military science and the way computers process data in a wartime environment. The CNO’s recent 2021 Navigation Plan stresses that “we are engaged in a long-term competition [with] China . . . and we must be prepared to flawlessly execute our Navy’s timeless roles of sea control and power projection. To preserve sea control and maintain a competitive edge in the Indo-Pacific amid rising Chinese aggression, the Navy must establish itself as a key player in the U.S. quantum technology community. To do so, the Navy should host operational testing on board its platforms in two critical areas: quantum cryptography and quantum sensing. The Navy’s operational tests in a rugged field environment will provide valuable feedback to the engineers who design the technology. Ultimately, the Navy’s role in the quantum development cycle will accelerate the process of transferring quantum technology from the laboratory to warfighting units.
Quantum Computing and Cryptography
Quantum computing is part of the larger quantum technology movement, which is “an emerging field of physics and engineering [that uses] the properties of quantum effects—the interactions of molecules, atoms, and even smaller particles” to solve problems. By leveraging these quantum effects, quantum computers process information differently from classical computers. Classical computers process binary information in 1s and 0s, whereas quantum computers use “qubits.” Instead of representing just 1 or 0, qubits can also exist in superposition, meaning that “they’re both on and off at the same time, or somewhere on a spectrum between the two.” With superposition, quantum computers can perform quick calculations by considering multiple potential outcomes instantaneously. Qubits also abide by the quantum principle of entanglement, meaning that “two members of a pair exist in a single quantum state [and] changing the state of one of the qubits will instantaneously change the state of the other one in a predictable way,” thereby increasing its computational power. A quantum computer’s use of qubits, and therefore the principles of superposition and entanglement, allow it to perform computations much more quickly than everyday binary computers.
By leveraging the unusual behavior of qubits to improve computing power, quantum computers pose a new threat to traditional cryptography. The modern standards of cryptography, which rely mainly on large prime number calculations to protect data, will not withstand a quantum system’s computational power. According to the Brookings Institution, “the need for unbreakable encryption is staring us in the face [and] with the development of quantum computers looming on the horizon, the integrity of encrypted data is at risk now.” With quantum computers, a hacker could break military-grade encryption in a matter of minutes, compromising secure communications. The best defense against malicious hackers with quantum capabilities is quantum key distribution, which the Los Alamos National Laboratory deems “the most powerful data encryption scheme ever developed [and is] by all indications, virtually unbreakable.”
China has already developed the “world's first integrated quantum communication network, combining over 700 optical fibers on the ground with two ground-to-satellite links to achieve quantum key distribution over a total distance of 4,600 kilometers for users across the country.” By constructing this network, China has set the pace for creating secure quantum communications that cannot be intercepted or manipulated. Further advances in Chinese quantum communication networks, especially networks designed for military use, will put the Navy at increased risk when deployed to the Indo-Pacific. If Chinese communications are virtually unbreakable and U.S. Navy communications can be exploited by Chinese quantum code-breaking technology, it will quickly lose its ability to safely operate among PLAN forces. While efforts to develop quantum key distribution are well underway with organizations such as Oak Ridge National Laboratory, it will be a long road from the design phase to battle-tested field use. However, the Navy can help speed up this process by partnering with research organizations to set up a wireless quantum key distribution network across multiple naval platforms. After the equipment is installed across these platforms, quantum technology developers could test the network at sea. Running these operational tests at sea would not only put this quantum technology through a “toughness test” in a challenging maritime environment, but it would also help developers soon tailor quantum key distribution networks for naval usage.
While quantum cryptography will be critical for secure military communications, quantum sensing will provide new capabilities for both stealthy open-ocean navigation and intelligence collection on foreign vessel locations. Quantum sensing—the use of quantum properties to measure changes in the surrounding environment—offers promising solutions to the chronic naval dilemma: dependence on GPS for navigation at sea. The Navy’s current dependence on GPS leaves platforms vulnerable to GPS-jamming while at sea. If a ship’s GPS downlink was jammed by a malicious Chinese signal, it would be unable to navigate safely in the open ocean. Though naval platforms also use internal navigation systems, these lose accuracy over time and require periodic GPS downlinks to confirm the vessel’s location.
Researchers at the Naval Postgraduate School are developing quantum sensing technology to “detect and track platform motion in the absence of GPS capabilities, such as underwater or in space.” Quantum sensing technology on board naval platforms would provide high-quality locational data without the need for periodic GPS updates, allowing the Navy to continue stealth operations in a GPS-denied environment. Beyond the clear navigational solutions it provides, quantum sensing could also be used for intelligence, surveillance, and reconnaissance (ISR) of foreign vessels. Quantum sensors that detect changes in the physical environment could “enable militaries to detect electromagnetic emissions . . . enhancing electronic warfare capabilities and potentially assisting in locating concealed adversary forces.”
Bringing quantum sensors to the fight would disrupt the traditional electronic warfare doctrine and provide increased situational awareness by revealing adversarial platform locations. Because most quantum sensing technology is tailored for national security use (unlike quantum cryptography, which offers immediate private sector benefits), the DoD must pick up the tab on this investment rather than rely on private industry to fund advancements in this technology. The Navy should take advantage of the research already completed at the Naval Postgraduate School and begin integrating this technology for operational testing at sea. To do this, the Navy should install rudimentary quantum sensors on board a submarine or surface ship and take this technology underway off the U.S. coast. Once underway, the Navy could test the sensor’s navigational accuracy and ability to detect small changes in the electromagnetic environment for ISR purposes. The real-world data collected during these sea trials would provide direct feedback to engineers to improve performance at sea.
While quantum technology R&D is a challenging and expensive endeavor, the Navy must be an integral part of the national quantum technology effort. By hosting at-sea operational testing for U.S.-produced quantum technology, the Navy will stay in the loop on emerging developments and be well suited to integrate quantum technology across the fleet permanently.
Because China’s quantum technology R&D is state-driven and U.S. quantum development is inherently more “disparate [and] spread across dozens of funding agencies, universities and private companies,” DoD leaders must ensure the development and application of quantum technology for military use is efficient. Partnerships with quantum technology developers and operational testing on Navy platforms will be key to leveraging this technology across the DoD for years to come. A failure to keep pace with China in the race for quantum technology will leave the DoD vulnerable to a myriad of threats in the Indo-Pacific. This is a race the United States cannot lose.