Abstract

Ensuring confidentiality in the transmission of digital data is a globally significant challenge. When necessary, data can be transmitted securely using cryptographic keys based on algorithms such as the RSA schemes. Even supercomputers lack the computational power to decrypt these keys. However, there is no guarantee that vulnerabilities won’t emerge. In fact, one vulnerability is already known: a sufficiently powerful quantum computer, when available, will render all RSA-based encryption systems vulnerable, affecting data transmitted worldwide.

Quantum and post-quantum communications represent the next steps in securing data. Quantum Key Distribution (QKD) is a technology that offers absolute security by leveraging the fundamental properties of quantum physics. Post-quantum techniques rely on sophisticated algorithms beyond RSA, even resistant to future quantum computers.

While the timing of cryptographic vulnerabilities remains uncertain, it’s certain that unprepared systems will become vulnerable overnight. Recognizing this challenge, Europe is constructing the “European Quantum Communication Infrastructure.” This ambitious project aims to design, develop, and deploy a QKD network to protect critical European infrastructure (government institutions, data centers, hospitals, energy grids, etc.) as a first step toward a complete European Quantum Internet. Catalonia has the opportunity to pioneer this field, starting with a quantum network in the Barcelona metropolitan area. This initiative will create a positive economic and business impact, making it an innovative and competitive reference within the Catalan, Spanish, and European ecosystems.The project, named Qollserola, has support from the Generalitat de Catalunya, the Spanish government, the Barcelona City Council, and the European Commission. It will contribute to fostering a national quantum ecosystem and is led by ICFO and Cellnex.