At the start of the Cold War, the western security apparatus sought to understand the actions of their adversaries by intercepting radio signals bouncing off the ionosphere. Later, when the Soviets moved to microwave transmissions, that same security apparatus deployed cutting-edge line-of-sight interception techniques. The U.S. National Institute of Standards and Technology is currently evaluating over 60 methods for post-quantum cryptography, quantum key distribution, and other security applications. Early indications are that quantum technology will provide an ability to detect, defend, and even retaliate against all manner of future threats. However, quantum computers will need considerably more processing power than is available today.
Source: https://www.helpnetsecurity.com/2021/06/04/quantum-computing-benefits/