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Quantum Cryptography in the US-China Tech Race

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Quantum Cryptography in the US-China Tech Race

Insights from Jonathan Dowling.

Quantum Cryptography in the US-China Tech Race
Credit: Illustration by Catherine Putz.

Trans-Pacific View author Mercy Kuo regularly engages subject-matter experts, policy practitioners, and strategic thinkers across the globe for their diverse insights into U.S. Asia policy. This conversation with Dr. Jonathan Dowling Professor and Hearne Chair of Theoretical Physics at Louisiana State University; visiting faculty member at the University of Science and Technology of China (USTC) in Shanghai; and recipient of NASA Space Act Award for Invention of Quantum Lithography is the 214th in “The Trans-Pacific View Insight Series.” 

Briefly explain China’s advances in quantum technology.

China’s particular strength is in the area of quantum cryptography. It has a secure network running between Beijing and Shanghai with quantum local area networks around those to cities as well as Hefei and several others. Most famously, China has the space satellite Mozi, whose primary mission is to establish quantum cryptography across China. Quantum cryptography is unbreakable by any means — even with a quantum computer. China was motivated to build this after the Snowden leaks and further motivated as other countries, such as the U.S., are quickly developing quantum computers that can hack anything not protected by quantum cryptography. They are also at the forefront of tests of the fundamentals of physics in space. In addition, with Mozi they have demonstrated quantum teleportation, that will be used in any quantum internet.

Analyze China’s progress in the context of the U.S.-China tech race.

For some time, my position was that China was ahead in quantum cryptography and that the U.S. was ahead in quantum computing. This has changed. The U.S. company Google announced that they hit Quantum Supremacy on their superconducting quantum computer — demonstrating that they can solve a problem on a quantum computer exponentially faster than on a classical computer. However, in a matter of days, University of Science and Technology in China announced that it had hit quantum supremacy with its all-optical quantum computer. At this point, China is now ahead of the U.S. with quantum cryptography and tied in quantum computing. I expect in five to ten years that China will be ahead of the U.S. in both categories.

Describe the military and commercial applications of quantum technology.

Quantum technology has many applications. The two I have discussed, cryptography and computing, will have direct applications to either securing (quantum cryptography) or hacking (quantum computer) commercial or government data on the internet. However, quantum computers have applications to practical problems such as the design of new medications and the simulation of new electronic materials. Quantum cryptography will eventually lead to a quantum internet of distributed quantum computers secured by quantum cryptography. Another application of quantum technology is sensing and imaging. Both China and the U.S. appear to be pursuing a remote sensing technology called “quantum radar” — but it is unclear how much of this is practical.

Identify key factors propelling China’s quantum research.  

As I mentioned, the rush to quantum cryptography was motivated by the Snowden leaks and the fear that the U.S. will have a code-breaking quantum computer first. But particularly in the group of Professor Pan Jianwei at USTC, the search for the fundamental workings of the universe — independent of any immediate applications — has always been a key direction in his research. With the Google and USTC announcements of quantum supremacy, we have reached a new era where quantum research will drive many — if not most — of the technological advances for the next 100 years. There is already a great interest in combining AI, which China is investing in heavily, with quantum computing — a new Quantum Artificial Intelligence.

Assess the U.S. national security implications of China’s strategy in developing quantum computing.

There are two right now that most worry the United States. The first is that in a few years, China will go dark behind a wall of quantum cryptography, and the U.S. will not be able to decode any of the information that is transmitted. The second is that the Chinese might develop the universal quantum computer first and be able to decipher all of the data being carried over the internet in the U.S. — since the U.S. has almost no effort in developing quantum cryptography nationwide.