This is the second in a series of two articles that examines and evaluates the ramifications of Chinese advances in quantum information science. While part 1 reviewed China’s national framework for and progress in this scientific domain, this second article evaluates the military applications and strategic implications of quantum technologies.
China’s high-level focus on quantum information science reflects its recognition of the revolutionary implications of quantum technologies. China has operationalized and employed “unhackable” quantum cryptography to secure sensitive communications, while pursuing quantum computing capabilities whose enormous computing power could overcome most existing forms of encryption. Concurrently, Chinese scientists are starting to explore other quantum technologies, including supposedly “stealth-defeating” quantum radar. The Chinese People’s Liberation Army (PLA) recognizes the strategic significance and operational potential of quantum technologies in their attempts to achieve a decisive advantage. Notably, these disruptive technologies—quantum communications, quantum computing, and potentially quantum radar—may have the potential to undermine cornerstones of U.S. technological dominance in information-age warfare, its sophisticated intelligence apparatus, satellites and secure communications networks, and stealth technologies.
The Military Applications of Quantum Technologies
Quantum Cryptography and Quantum Communications
The employment of quantum cryptography enables unbreakable, almost unhackable quantum communications networks that may have particular utility in a military context. Currently, China is in the process of constructing these networks at a national and even global scale for government and military purposes (see part 1). The PLA may already employ quantum communications networks in a limited capacity for the transmission of particularly sensitive information. By contrast, the U.S. military has not yet chosen to invest extensively in building a quantum communications infrastructure. For instance, the Air Force has concluded that the technique of quantum key distribution “significantly increases system complexity but is unlikely to provide an overall improvement in communication security” (USAF Scientific Advisory Board). For the PLA, however, existing communications systems are presumably relatively insecure, such that the value-added of state-of-the-art quantum communications may be higher. The construction of a national quantum communications backbone network (国家量子通信骨干网) has been characterized as a form of military-civil fusion (MCF, 军民融合), consistent with a national strategy for MCF and a tradition of building infrastructure optimized for such dual uses (Xinhua, November 21).
Looking forward, the PLA will likely use increasingly sophisticated quantum communications networks not only to ensure the integrity of sensitive communications during peacetime but also to seek an asymmetric information advantage in a conflict scenario. As China’s concern about the security of military and civilian information systems has intensified, the employment of quantum cryptography has come to be seen as a critical “shield” for information security (信息安全之“盾”) (USTC, August 16). In one early application of this technology, in 2009, a team of scientists under the leadership of Pan Jianwei constructed a quantum network to secure communication between government officials coordinating the military parade that celebrated the 60th anniversary of the founding of the People’s Republic of China (Caixin, February 6, 2015). Although it is difficult to verify the current status of the PLA’s quantum communications capabilities, Pan Jianwei claimed in an interview last year, “China is completely capable of making full use of quantum communications in a local war. The direction of development in the future calls for using relay satellites to realize quantum communications and control that covers the entire army” (Caixin, February 6, 2015). This is why China’s quantum satellite, Micius (墨子), is so important, since it enables the testing of this methodology, while also advancing progress toward a future “quantum Internet.” By 2030, China intends to possess a network of quantum satellites, which could potentially also be employed not only to enable secure military communications but also to enhance the PLA’s command and control capabilities, including perhaps the secure transmission of the targeting data necessary to enable long-range precision strike (e.g., PLA Daily, September 27).
PLA academics have highlighted the multiple applications and potential advantages of quantum communications in a military context. According to National Defense University professor Li Daguang (李大光), quantum communication could contribute to ensuring information security, enhancing information confrontation capabilities, and enabling superluminal (i.e., faster than the speed of light) communication (PLA Daily, March 24). As a result, multiple nations are “racing to control the strategic commanding heights of quantum communication.” Influential PLA information warfare theorist Ye Zheng (叶征) has also characterized quantum cryptography as one of the emerging technologies that have “infused information operations with new vitality, promoting the development of information operations.”  According to An Weiping (安卫平), deputy chief of staff of the PLA’s new Northern Theater Command, quantum communication is anticipated to have a dramatic impact on the future evolution of the form of warfare and the international military balance, including because it is anticipated to enhance battlefield information processing facilities, enabling the construction of a more robust combat system (PLA Daily, September 27).
Although the value of quantum cryptography is debatable, recent Chinese advances in quantum key distribution do constitute significant steps toward the development of even more secure quantum communications networks optimized for wartime use.  In November, a paper co-authored by Pan Jianwei described recent advances in measurement-device-independent quantum key distribution, which overcomes potential security vulnerabilities, including through detecting attempted eavesdropping (Phys. Rev. Lett., November 2). Notably, their research broke records through secure transmission over 404 kilometers of optical fiber, while concurrently demonstrating a 500-fold increase in speed, sufficient to enable encrypted voice transmission via telephone (Physics, November 2). While this demonstration is only experimental at this point, continued advances in quantum communications could further increase its utility for the PLA.
The eventual achievement of quantum computing will result in computational capabilities that are vastly more powerful than classical computers. Future quantum computers could be integrated into complex weapons systems that require immense processing power. Through quantum computing, it will become possible to overcome most standard forms of encryption, rendering all networks reliant upon it, including computers and satellites, extremely vulnerable. In future warfare, quantum computing may prove to have strategic significance on par with nuclear weapons (e.g., PLA Daily, January 8, 2014).
For the PLA, the pursuit of quantum computing may possesses particular strategic significance since this capability could undermine the security of the extensive network of communications and surveillance satellites upon which the U.S. military remains heavily dependent. The PLA considers the U.S. to be a “no satellites, no fight” military and has focused on multiple kinetic and non-kinetic methods of targeting U.S. space assets.  PLA doctrinal writings have also emphasized the targeting of isolated battlefield networks, such as those of a carrier battle group. 
Within our lifetimes, quantum computing will enable such attacks on the availability and integrity of the satellites and communications systems upon which modern warfare relies, in ways currently inconceivable. The ability to decrypt sensitive intelligence and communications, whether conveyed via satellite networks or fiber, would provide an extreme intelligence advantage in peacetime and wartime contingencies alike. In the foreseeable future, a major, very real threat facing the U.S. is the possibility that a strategic competitor, such as China, could develop quantum computing in secret and use it against sensitive communications in order to outmaneuver or strategically outflank the U.S. In a wartime scenario, this potential infiltration of isolated networks could enable efforts to preempt operational movements or sabotage U.S. systems, without the U.S. knowing the source of this vulnerability. Although the full extent of U.S. government and military advances in quantum computing is likely not reflected by the limited information available in the public domain, the U.S. has yet to articulate a national agenda for quantum science that matches the scope or scale of that of China. Recently, a White House official articulated concerns that the U.S. lead in quantum computing is increasingly “under siege” (Defense One, December 7).
In the perhaps more distant future, various forms of quantum sensing, including quantum radar, may take advantage of quantum entanglement to enable highly sophisticated detection of targets, regardless of stealth.  Notably, in September, a team of Chinese scientists from China Electronics Technology Group Corporation’s (CETC) 14th Research Institute’s (中国电子科技集团第14研究所) Intelligent Sensing Technology Key Laboratory (智能感知技术重点实验室) publicized their progress toward creating a single-photon quantum radar that is reportedly capable of detecting targets up to 100 kilometers away with improved accuracy (PLA Daily, September 13; CETC, September 18). Their research was undertaken in collaboration with a team led by Pan Jianwei from the University of Science and Technology of China, CETC’s 27th Research Institute, and Nanjing University (CETC 14th Research Institute, September 7). The reported range of this quantum radar, which takes advantage of entanglement between photon pairs, is supposedly five times that of a laboratory prototype jointly created last year by an international team of researchers (Phys.org, February 26, 2015).
The future realization of quantum radar that could potentially overcome superior U.S. stealth capabilities would enable the PLA to undermine this critical pillar of U.S. military power. At the time, commentary in PLA media highlighted quantum radar as the “nemesis” of today’s stealth fighter planes, highlighting that it has “remarkable potential” to disrupt future warfare (PLA Daily, September 22). However, it is difficult to evaluate the actuality of China’s advances in quantum radar technology. Information in official media reports of technological breakthroughs could potentially be exaggerated. On the other hand, the possibility that certain aspects of Chinese research on the military applications of quantum technologies may have advanced further than is discernable based on the available open-source information and publications also cannot be discounted.
The Chinese Defense Industry’s Development of Quantum Technologies
Beyond the academic laboratories and research institutes focused on quantum information science (e.g., see part 1), several Chinese state-owned defense firms also appear to have started to engage in research and development regarding the military applications of quantum technology. These include: the China Electronics Technology Group Corporation (中国电子科技集团, CETC), one of China’s top state-owned defense conglomerates, which has close ties to the PLA and China’s space program, as well as the China Aerospace Science and Industry Corporation (中国航天科工集团公司, CASIC) and China Aerospace Science and Technology Corporation (中国航天科技集团公司, CASC), state-owned defense firms that act as primary contractors for China’s space program and also develop related military technologies (China Brief, February 21, 2012). The following is an initial listing of the research institutes associated with these defense firms that are reportedly engaged in research in quantum technologies.
The Future of Warfare in the Quantum Age?
Looking forward, China aspires to lead the coming second quantum revolution and may possess the potential to leapfrog the U.S. in this critical technological domain (PLA Daily, August 18). According to An Weiping, as the information age is undergoing a “leap” toward the “quantum information age,” quantum is considered the “forward position” for a great power’s comprehensive national power, scientific level, and strategic contests of military power (PLA Daily, September 27). China’s concentrated pursuit of quantum technologies could have much more far-reaching impacts than the asymmetric approach to defense that has characterized China’s strategic posture thus far, with its focus on “assassin’s mace” (杀手锏) programs since the 1990s.
These quantum ambitions seemingly constitute an evolution of the PLA’s traditional asymmetric strategy to one that attempts to offset U.S. technological superiority. The employment of quantum communications, computing, and perhaps even radar may radically alter the rules of the game on the future battlefield. These technologies could neutralize the technological advantages associated with today’s information-centric ways of war, epitomized by the U.S. model, which has relied upon a sophisticated global intelligence apparatus, military satellite networks, and stealth capabilities. For China, the successful development of even one or two of these quantum technologies might ultimately enable an “offset” of its own, which could decisively change the future strategic balance.
John Costello is a Senior Analyst for Cyber and East Asia at Flashpoint. He is a Cybersecurity Fellow for New America and former Congressional Innovation Fellow for the majority staff in the U.S. House of Representatives Committee on Oversight and Government Reform. John is also a U.S. Navy veteran, former NSA Analyst, and is fluent in Mandarin Chinese.
Elsa Kania is currently an analyst at the Long Term Strategy Group. She is a graduate of Harvard College (summa cum laude, Phi Beta Kappa). Elsa was a Boren Scholar in Beijing, China, and she is fluent in Mandarin Chinese. Her prior professional experience includes working at the Department of Defense, FireEye, Inc., and the Harvard Kennedy School’s Belfer Center for Science and International Affairs.
- Ye Zheng [叶征], Lectures on the Science of Information Operations [信息作战学习教程], Military Science Press [军事科学出版社], 2013, p. 79.
- The substitution of conventional encryption by quantum key distribution does not eliminate other vulnerabilities and weak links in the security of a system (e.g., Schneier on Security, October 16, 2008). In some cases, the complexity introduced by this quantum cryptographic technique may also limit the efficacy of this technology (e.g., USAF Scientific Advisory Board).
- See, for instance: Kevin Pollpeter, “The Chinese Vision of Space Military Operations,” in China’s Revolution in Doctrinal Affairs: Emerging Trends in the Operational Art of the Chinese People’s Liberation Army, 2005, p. 329–370.
- Ye Zheng [叶征], Lectures on the Science of Information Operations [信息作战学习教程], Military Science Press [军事科学出版社], 2013, p. 91.
- In general, there are three primary forms of quantum radar, single-photon quantum radar (单光子量子雷达), interferometric quantum radar (干涉式量子雷达), and quantum entanglement radar (以及纠缠态量子雷达). Although there is limited information available about which forms of quantum radar may be currently in research and development in China, there have been patents filed for a “laser radar based on the principle of strongly correlated quantum imaging” (Zhejiang University, May 7, 2010), quantum radar and target detection methods (Tan Hong, October 22, 2014), and a “quantum entanglement radar” (Ge Wangshan, June 15, 2012).
- Sources for chart is as follows: CETC 14th Research Institute, September 7; Patent; CETC 38th Research Institute; China Popular Science Reader, November 3, 2009; Sina, August 31; CASC, August 20, 2015; China Space News, July 26, 2012.