Thanks to the implementation of quantum key distribution technology by the Academic Computer Centre Cyfronet AGH, the City of Kraków has become the first institution to be connected to a computing centre using this solution.
This marks a breakthrough that opens a new era of secure communication and strengthens Kraków’s position as a city investing in the most advanced—quantum—cybersecurity solutions.
A quantum shield for Kraków
Quantum Key Distribution (QKD) is one of the most advanced cryptographic technologies available today. It uses the laws of quantum mechanics to generate and transmit encryption keys. Its uniqueness lies in the fact that any attempt to intercept the transmission automatically destroys the key and triggers an alert. The keys are generated in real time, eliminating the need for storage and ensuring the highest possible level of protection.
Specialists from the Academic Computer Centre Cyfronet AGH designed, built, and launched a quantum key distribution system between the City of Kraków Office and Cyfronet AGH. This is the first connection of its kind in the region, enabling the transmission of encryption keys used to secure a network link with a bandwidth of 100 Gbps (gigabits per second).
“Thanks to this solution, secure data transfer between institutions is possible—for example for archiving purposes, database exchange, data analysis, or enriching the content of the City of Kraków Office’s information services,” explains Karol Krawentek, Deputy Director of the Academic Computer Centre Cyfronet AGH for Data Centre Infrastructure.
Kraków’s Digital Shield—stronger than ever
Quantum key distribution is a security technology that significantly surpasses current standards. It represents an important step toward counteracting potential threats related to the future use of quantum computers to break today’s encryption methods. As a result, QKD technologies help protect Kraków’s critical infrastructure.
The implementation of quantum key distribution is the result of cooperation between the AGH University of Science and Technology and the City of Kraków Office, expanding one of the core assumptions of the Digital Shield of Kraków: preventing threats in cyberspace before they occur.
“This is not a project for today only, but an investment in Kraków’s security for decades to come. When we signed a letter of intent with AGH, we said we wanted to stay ahead of cyber threats—today we are showing that we can move from declarations to concrete, groundbreaking implementations. Quantum key distribution represents the highest possible standard of data protection, based on the laws of physics rather than compromises. Thanks to cooperation with AGH and Cyfronet, Kraków is building its digital security on science, innovation, and responsibility for residents’ data, while becoming an active participant in European efforts toward secure communication of the future,” emphasizes Aleksander Miszalski, Mayor of Kraków.
How does it work?
“Quantum key distribution technology is based on quantum-secured communication between a pair of devices. On the Cyfronet side, one device generates keys using a quantum random number generator. The keys are then passed to an encryptor, which secures the connection between the City Office and Cyfronet. On the City of Kraków Office side, a second device receives the keys and forwards them to a local encryptor responsible for encrypting and decrypting data within the Office,” explains Marek Chorąży, a quantum technologies specialist at Cyfronet and the lead engineer of the QKD system implementation.
Quantum key distribution is considered unbreakable. It is based on the laws of physics rather than mathematical assumptions. This means that any attempt to eavesdrop on or copy a key immediately destroys or distorts it, thereby revealing the presence of an intruder trying to intercept the transmitted message or data. Unlike classical encryption, the key does not exist as an object that can be copied; instead, it is generated and transmitted in a way governed by quantum mechanics, effectively eliminating the possibility of interception without detection.
Part of a broader ecosystem
The data protection infrastructure developed by Cyfronet specialists further expands the range of services offered by the centre to the academic community and businesses.
“Out of concern for the security of processed data, a QKD connection has also been established between Cyfronet’s main and backup data centres. Given the shared use of the computing resources of our Ares, Athena, and Helios supercomputers, as well as our storage systems, it is crucial that data transmitted between the two locations is protected at the highest possible level,” emphasizes K. Krawentek, Deputy Director of the Academic Computer Centre Cyfronet AGH.
A European infrastructure
The implementation of quantum key distribution technology in Kraków between Cyfronet and the City of Kraków Office is part of a much larger European initiative. Its goal is not to build isolated secure links, but to create an extensive network covering the entire European Union.
In Poland, such connections are being developed under the PIONIER-Q project and include links between high-performance computing centres and selected municipal computer network hubs. In the years 2026–2028, as part of the European Quantum Communication Infrastructure (EuroQCI) initiative, Cyfronet—together with its partners—will build connections to countries located close to Poland. The resulting network is intended to protect sensitive data and critical infrastructure by integrating systems based on quantum mechanics with existing communication infrastructure, providing an additional layer of security.
The creator of quantum key distribution is Professor Artur Ekert, a pioneer of quantum cryptography associated with the University of Oxford and the National University of Singapore. He was one of the first scientists to propose using the laws of quantum mechanics to secure information transmission. Engineers at AGH therefore rely on a method first proposed in 1991. Although quantum key distribution is not yet widely used, it continues to develop and has strategic importance for the security of critical infrastructure, satellite communications, and data protection.
Source: ceo.com.pl
