Quantum ‘keys’ secure nuclear reactor communications

Purdue College of Engineering
Purdue Engineering Review
5 min readSep 13, 2022

The nuclear industry is embarking on a transformation that will result in a more reliable and efficient new generation of advanced reactors, the success of which eventually will determine its future. Advanced reactors are being proposed with new capabilities — such as remote and semi-autonomous operations — as well as more flexible functioning, plus ability to transition toward a more connected, “smart” electric grid.

However, success for new reactors will require more than compatibility with digital technologies focused on optimizing plant operation. Next-generation reactors will also need the capability to be integrated into a modern electrical power grid that is based on information technologies, rather than the conventional, one-directional power flow of today.

The environment of the electrical grid is changing to an interconnected system of distributed energy sources and two-way information and communication systems. Recent power system attacks highlight the rapid evolution of interception technologies, and further emphasize the importance of cybersecurity based on the information flow. Thus, the first step to minimize potential cyber threats is to ensure the confidentiality of communications.

In cryptography, there are several encryption schemes that cannot be cracked if enacted correctly. The main problem with all encryption strategies is the sharing of the secret key, which must be distributed securely between sender and receiver. To address this challenge, our research team at Purdue University’s RADIaNS (Radiation Imaging and Nuclear Sensing) Lab is studying the implementation of quantum key distribution (QKD) for nuclear communications.

(Purdue University image/RADIaNS Lab)

QKD can improve the level of communication security, and has attracted attention in critical areas like national defense, finance, and government. Various countries have proposed plans to build QKD networks to ensure safe transmission and data privacy. Yet despite this promise of better security, there is limited research into the practical application of QKD technology in the nuclear industry.

The nuclear industry has different security requirements than other sectors due to its extremely high needs for availability of command signals and its restricted bandwidth. As a result, it is necessary to evaluate not whether QKD can offer better security, but which QKD solutions are best and where they should be implemented.

QKD is based on physical principles of quantum mechanics, instead of mathematical functions with high computational complexity. It is a physical-layer security scheme that exploits the laws of quantum mechanics. It guarantees provable security even against a quantum-computer-initiated attack, because it is verified without making assumptions about the eavesdropper’s computational power or strategy. Built on the “no-cloning theorem” — which states that a random unknown quantum state cannot be cloned — QKD is able to reveal to the communication participants whether an eavesdropper is present, as well as how much information the attacker has gained.

We are working on developing and implementing a quantum encryption scheme optimized for nuclear communications via a QKD testbed under development at Purdue. The testbed is coupled with the fully digital instrumentation and control system of the Purdue University Reactor (PUR-1), enabling data from sensors and control rod movements to be encrypted through a quantum-based communication network from a remote-control center. We anticipate that this approach will enable secure communications for advanced nuclear reactors and further expand the use of quantum-based communication networks.

This evolving experimental setup allows direct control of the position, speed and orientation of an auxiliary control rod. The movement is controlled through an actuator, which is operated after receiving commands from a digital controller. In addition, the testbed enables us to collect sensor data for the height and the speed of the control rod, as well as real-time reactor data. The secure quantum-based channel is used for the communication between the testbed and the remote-control room.

Alongside the operational control, the experimental setup enables us to simulate cyberattacks by using an “attacker” computer that can intercept reactor control room communications. The collected data processed through the quantum-based channel are compared with the original reactor’s data; this can indicate any imperfections or faults in the testbed layout and the quantum-based secure network. We anticipate the testbed will stimulate commercial use of quantum-base cybersecurity systems in remotely-controlled digital nuclear reactors.

Stylianos Chatzidakis, PhD

Assistant Professor of Nuclear Engineering

Associate Reactor Director, Purdue University Reactor Number One (PUR-1)

Director, Nuclear Engineering Radiation Laboratory

School of Nuclear Engineering

College of Engineering, Purdue University

Konstantinos Gkouliaras

Graduate Research Assistant

School of Nuclear Engineering

College of Engineering, Purdue University

Vasileios Theos

Graduate Research Assistant

School of Nuclear Engineering

College of Engineering, Purdue University

Reshma Ughade

Graduate Research Assistant

School of Nuclear Engineering

College of Engineering, Purdue University

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