Quantum technologies, U.S.-China strategic competition, and future dynamics of cyber stability

The current realities of the cyber domain could be radically disrupted by the advent of quantum communications and quantum computing. The consequent challenges for future cyber security and strategy require a nuanced analysis of these technologies and their likely employment by major powers. The employment of quantum cryptography can create quantum communications systems that are theoretically unhackable. Within the foreseeable future, quantum computing will be powerful enough to overcome most of today's advanced encryption techniques, rendering the majority of existing commercial, government, and military systems unprecedentedly vulnerable. These quantum technologies could respectively tend to advantage defense and offense in the cyber domain. While the “shield” enabled by quantum communications would contribute to technological deterrence through denial, the asymmetries of vulnerability that might result could potentially undermine military cyber stability, while exacerbating the risks of misperception through complicating intelligence collection. In the more distant future, the advent of quantum computing will enable unique offensive power that could leapfrog existing cyber capabilities. The strategic impact of these disruptive technologies will depend upon the approaches of great powers, particularly the U.S. and China, which have become leaders in this technological domain.