Building Quantum-Safe Mobile Networks: The PQ-REACT QKD on 5G Pilot with Antonio Pastor
In this episode of PQ-REACT: Conversations with our Experts, we discussed with Antonio Pastor from Telefónica about the QKD on 5G networks pilot’s objectives, testing environment, key findings, and the role quantum-safe technologies will play in securing 5G and future 6G infrastructures.
We hear a lot about both quantum threats and quantum solutions these days. In the context of 5G networks, what is the core challenge this pilot is trying to tackle?
5G is the result of more than four decades of technological evolution and today supports critical communications, services, and digital infrastructure across Europe. Preparing these networks for the quantum era is therefore not optional, it is a strategic necessity.
Although 5G already incorporates a strong security foundation, it is not fully protected against future quantum-enabled attacks. While some protection mechanisms remain robust today, critical areas such as backhaul communications and core network interconnectivity for roaming services will require additional safeguards to ensure long-term resilience.
The telecommunications sector is already moving in this direction, and future 6G standards are expected to incorporate quantum-safe requirements from the outset. The core challenge addressed by this pilot is understanding how mobile operators can integrate both post-quantum cryptography and Quantum Key Distribution (QKD) into 5G and future 6G environments without compromising performance, scalability, or operational viability.
The pilot focuses on identifying where mobile infrastructures are most exposed and validating how quantum-safe technologies can be integrated in realistic, scalable, and operator-ready scenarios. Ultimately, the goal is to transform quantum resilience from a theoretical objective into a practical capability for next-generation mobile networks.
How will the pilot be tested? Can you give us a few details?
The pilot is being validated within a representative 5G environment designed to generate measurable research evidence. Several PQ-REACT technologies are combined, including 5G digital twinning capabilities, post-quantum cryptography mechanisms, and Quantum Key Distribution integration.
The pilot extends IPsec-based backhaul communications with quantum-safe protection mechanisms while also deploying monitoring and assessment tools such as CUHATA and the PQ-REACT Cryptographic Agility Manager. The objective is to evaluate how these protections perform under realistic but controlled operating conditions, measuring factors such as resilience, efficiency, and operational impact.
“This approach enables the project to move beyond theoretical assumptions and generate results that are directly relevant to future secure network deployments.”
How will the pilot help solve the challenges you described earlier?
The pilot provides actionable evidence that supports decision-making for operators, technology providers, and policymakers. Through practical testing, it demonstrates which quantum-safe approaches can be integrated into mobile networks, under which conditions they perform effectively, and what operational implications they may have.
This evidence is critical because the transition to quantum-safe security can only succeed if supported by validated data regarding resilience, scalability, and performance.
And which solutions will be generated through this pilot implementation?
The pilot generates a set of validated integration pathways for introducing post-quantum cryptography and Quantum Key Distribution into mobile network environments. Its output includes practical deployment knowledge, performance assessments, and open technological components that can support future adoption across the telecommunications sector.
“Most importantly, the pilot provides the research evidence needed to guide future implementation decisions and accelerate the adoption of quantum-safe security solutions.”
You are working with some of the most advanced network infrastructure in Europe, including the largest QKD network. What does that enable you to do that wouldn’t be possible otherwise?
Access to advanced experimental infrastructures provides a significant advantage. Quantum Key Distribution requires dedicated fibre connectivity, specialised hardware, and integration within real networking environments.
Through access to initiatives such as the European Quantum Communication Infrastructure (EuroQCI) and experimental networks including MADQCI and Telefónica’s TFQCI infrastructure, the project can test QKD and post-quantum technologies far beyond laboratory conditions.
This allows the team to validate solutions in environments that closely resemble operational reality and generate results that are directly applicable to future deployment decisions.
What are the foreseen impact and benefits of this pilot on the main PQ-REACT stakeholders and also on EU citizens? Which results from this pilot will ensure a smooth transition to the quantum era?
The impact of this pilot is significant for both industry stakeholders and citizens.
For network operators, technology providers, and other industry stakeholders, the pilot delivers validated research results, tested integration methodologies, and open technological components that can accelerate the adoption of quantum-safe security solutions.
For European citizens, the benefits are equally important. As 5G increasingly becomes a core component of everyday digital life, strengthening its protection against future quantum threats helps preserve the security, reliability, and trustworthiness of the services people depend upon.
The pilot’s findings contribute to ensuring that critical communications infrastructures remain secure throughout the transition to the quantum era, supporting a smoother and more reliable migration process for all stakeholders involved.
What has this pilot taught you—key takeaways? And where do you see this sector heading in the years to come?
One of the most important lessons from this pilot is that the transition to quantum-safe security cannot be approached as a simple cryptographic replacement. The challenge affects multiple layers of the telecommunications ecosystem, including software platforms, network architectures, and operational processes. Success depends not only on technical feasibility but also on performance, scalability, and long-term sustainability.
The research conducted within PQ-REACT has confirmed this reality.
At the same time, the transition is not being tackled by a single organisation. The wider telecommunications ecosystem is actively working to incorporate quantum-safe technologies into future generations of mobile communications, particularly 6G. Standardisation bodies such as 3GPP have already begun studying these topics and defining future directions. The work carried out through this pilot contributes valuable insights that can support these efforts and help shape the next generation of secure mobile networks.
“As the sector moves forward, quantum-safe security is expected to become a fundamental requirement rather than an optional enhancement, ensuring that future communications infrastructures remain resilient in an increasingly complex technological landscape.”
Listen to the full discussion here.