A millennia-old problem will finally be solved: ever since humans have been sending messages, people have been trying to keep these messages secret. Countless encryption methods have been developed – and countless techniques to crack these encryptions. However, this old race between coding and code-breaking is now likely to be decided by quantum physics: It allows encryption methods that, in principle, cannot be cracked. The basic laws of nature forbid it.

This concept has been known for decades as “quantum cryptography”. The basic ideas have long been included in quantum textbooks. However, on closer inspection, the matter is somewhat more complicated: no quantum system is perfect, and it is necessary to carefully analyse whether this results in weaknesses and how to deal with them. This is why the new research project “Numerical Security Proof Toolkit for Quantum Key Distribution” has been launched, which is intended to make quantum cryptography ready for use in industrial practice over the next two and a half years in Vienna and Innsbruck.

Quantum Key Distribution (QKD)

“In quantum key distribution, the laws of quantum physics are used to generate identical sequences of random numbers at two different locations at the same time. This numerical code can then be used for encryption” explains quantum physicist Prof Gláucia Murta from the Atomic Institute at TU Wien. “If a third party tries to intercept this numerical code, they have to intervene in the experiment, and according to the rules of quantum theory, this is not possible without changing the result. This can be proven – so if the experiment is successful, you can guarantee that nobody secretly obtained the key.”

“There are mathematical proofs for the security of quantum key distribution systems, but they assume perfect quantum devices, which is far from reality,” says Dr Max Riegler, project lead at qtlabs. “This has repeatedly led to criticism. We now want to correctly take into account the imperfections of today's devices and find ways to still be able to guarantee absolute security in data transmission.”

Theory, experiment, law and ethics

This requires theoretical work as well as technical improvements. Legal and ethical aspects are also being analysed in the research project. The University of Innsbruck team, led by Prof. Dr. Matthias C. Kettemann, is exploring how standards and regulations can be developed to ensure fairness and reduce digital inequalities. “It’s crucial that advancements in quantum encryption benefit everyone,” emphasizes Prof. Kettemann. The Innsbruck team is also analyzing how international and European norms for critical infrastructure align with the certification standards the toolkit will establish.

By the end of the project, the team aims to deliver a software toolkit to help businesses and institutions evaluate and certify their QKD systems. The initiative represents a major step toward making QKD an integral part of modern cybersecurity solutions, ensuring Europe remains competitive in the quantum age.

Contact:

Prof. Gláucia Murta Institute for Atomic and Subatomic Physics TU Wien +43 1 58801 141833 glaucia.murta@tuwien.ac.at