Researchers at DTU have made a significant breakthrough in quantum-secure key distribution by successfully distributing a quantum-encrypted key over a record distance of 100 km using Continuous Variable Quantum Key Distribution (CV QKD). This method holds potential for securing data transfers against eavesdropping and surveillance, especially as quantum computers pose a threat to existing encryption algorithms. While quantum computers are not yet powerful enough to break these algorithms, it is only a matter of time before they can do so, making it crucial to develop new encryption methods based on quantum physics principles.
Quantum Key Distribution (QKD) utilizes the unique properties of quantum mechanical particles known as photons to exchange cryptographic keys between sender and receiver securely. The quantum state of the photons is altered if an attempt is made to measure or observe them, making it impossible for a third party to intercept the key without detection. This technology is essential for protecting critical infrastructure such as health records and the financial sector from potential hacking attempts, ensuring data security and privacy.
CV QKD technology can be integrated into existing internet infrastructure, leveraging optical fibre cables used in traditional communication systems. By adapting this technology to work over longer distances, it is possible to extend the reach of quantum-secure key distribution to facilitate secure communication networks between different locations. The success of distributing a quantum-encrypted key over 100 km demonstrates progress towards establishing quantum-safe communication between cities and secure communication networks for organizations and ministries.
To overcome challenges in exchanging quantum-encrypted keys over longer distances, researchers have implemented machine learning techniques to detect and mitigate noise or disturbances that could impact the system’s performance. By addressing factors such as noise, errors, and imperfections in hardware, the researchers have enhanced the reliability and efficiency of CV QKD technology. This progress will enable the establishment of secure communication networks for government ministries and businesses with branches in different cities, ensuring quantum-safe communication channels.
Quantum Key Distribution, first conceptualized in 1984 and practically implemented in 1992, relies on the uncertainty and randomness inherent in quantum states of light to prevent unauthorized access to encrypted data. Photons in a quantum state exhibit uncertainty in terms of their number and randomness in terms of their superposition states, making it extremely challenging for hackers to intercept keys without introducing errors. By focusing on the smooth properties of quantum states in photons, CV QKD enhances the security of quantum-secure key distribution, making it virtually impossible for hackers to intercept or replicate keys without detection.
Supported by various funding sources, including the Innovation Fund Denmark and the European Union’s Horizon Europe program, the research group at DTU, comprising Adnan A.E. Hajomer, Nitin Jain, Hou-Man Chin, Ivan Derkach, Ulrik L. Andersen, and Tobias Gehring, is dedicated to advancing quantum communication technologies. The Danish Quantum Communication Infrastructure (QCI.DK) aims to deploy Danish quantum communication technologies in a versatile network to support real-world applications of Quantum Key Distribution. By leveraging CV QKD technology and machine learning techniques, researchers are making significant strides towards establishing secure communication networks and enabling quantum-safe data transfer over extended distances.
