Quantum Cryptography: The Future of Secure Communication

For a long time, RSA and elliptic curves were considered the unshakeable pillars of modern IT security. But the rules of the game are changing: the rapid development of quantum computers is making a scenario realistic in which even the strongest encryption could become obsolete.

No quantum computer is yet capable of breaking RSA-based or ECC-based systems within practical timeframes. But the risk of “harvest now, decrypt later” is real: data that is encrypted and stored or transmitted today could be decrypted in the future once sufficiently powerful quantum computers become available.

The turning point in cryptography

For companies, this means the countdown is on. Anyone who wants to protect sensitive data in the long term must start now to make their security architecture “quantum-safe.” Experts have now developed two key strategies for securing communications against quantum attacks. 

One is post-quantum cryptography (PQC), which is based on classical, mathematically novel methods that cannot be efficiently solved even with quantum computers. The other is quantum cryptography in the narrower sense, which uses physical effects to make eavesdropping attempts measurable.

Both approaches pursue the same goal, but with different logic. PQC can largely be implemented on existing IT infrastructures and usually only requires software updates. Quantum cryptography, on the other hand, requires special hardware such as photon sources or detectors, and often functions via fiber optic or satellite connections. In return, it offers a level of security based on the fundamental laws of physics – eavesdropping simply becomes detectable.

The future will likely lie in a combination of both approaches: in hybrid systems that combine PQC algorithms with quantum-safe key exchange, thus creating a multi-layered security model.

With the publication of the first post-quantum standards by the US National Institute of Standards and Technology (NIST) in the summer of 2024, the era of quantum-safe cryptography has been officially inaugurated. For the first time, binding procedures are in place that are intended to serve as a new international basis for secure communication. This decision has implications far beyond the research sector: it marks the beginning of a global transition to new cryptosystems. Major technology providers such as Google, Microsoft, and Amazon have already begun to align their security protocols with these new standards. Even everyday applications such as web browsers and messaging services are now testing connections that are hardened against quantum attacks.

From research to practice

For Europe, and Germany in particular, this means that the foundations have been laid, and implementation must now follow. If companies and public institutions hesitate too long, they risk being left behind by international developments. Those who integrate the new standards early on will not only secure their own communications, but also technological sovereignty in the digital space.

Germany is well positioned to play a leading role in the secure communication of the future. Research institutions, high-tech companies, and government actors are already working on projects that test quantum-safe networks, new encryption methods, and interoperable infrastructures. The key now is to bring these approaches more quickly to scale – from pilot experiments in laboratories to operational solutions in administration, industry, and cloud infrastructures. This requires coordinated measures on multiple levels: clear responsibilities, binding timelines for the transition to post-quantum standards, and incentives for companies to invest in quantum-safe technologies.

It is particularly important to link research, regulation, and application. When government authorities, standardization bodies, and industry work together, Germany can take on a pioneering role in Europe. This also includes examining existing IT systems for their quantum readiness at an early stage: which systems need to be modernized, which key management processes need to be adapted, and which communication interfaces need to be hardened? With targeted support, international cooperation and decisive action, Germany can not only catch up, but actively shape the transformation and influence standards, rather than simply adopt them. The time to act is now.

This transformation can be well paraphrased as “From Lab to Fab” – that is, the path from research to industrial reality. Quantum communication and quantum hardware are still expensive and complex, and the use of quantum resources can cost several thousand euros per hour. But the technology is developing rapidly. New approaches such as continuous variable Quantum Key Distribution (QKD) or hybrid cloud models are lowering the entry barriers, and initial real-world laboratories demonstrate that quantum channels can be combined with classical infrastructure.

In Germany, companies and research institutions are already testing quantum-safe networks. Deutsche Telekom and various Fraunhofer Institutes are among the pioneers. The race is also on internationally: quantum backbones are emerging in Asia and North America that could form the backbone of secure communication in the long term.

For IT decision-makers, this presents a dual challenge – but also a great opportunity. Protection against quantum attacks first requires a precise understanding of one’s own cryptographic landscape: which systems use classical public-key procedures, where are certificates, VPNs, or encrypted emails used, and how long must data remain confidential?

Securing competitive advantages, averting dangers

On this basis, companies can migrate step by step: starting with hybrid methods that combine classic and quantum-safe components, followed by full implementation of new standards. At the same time, it is important to sensitize employees and management to the risks and opportunities of quantum technology. In the long term, organizations that invest in research partnerships and launch pilot projects today will not only secure their data, but also secure competitive advantages. Quantum readiness is no longer a technical option – it’s becoming an integral part of responsible corporate governance.

In the coming years, the vision of a global “Quantum Internet” will increasingly take shape – a network that can transmit quantum information over long distances and physically guarantee eavesdropping security. Advances in quantum repeaters, satellite-based QKD, and error-corrected quantum networks make this prospect seem more realistic than it did just a few years ago.

At the same time, hybrid security architectures are emerging in which classical cloud systems and quantum-based communication channels coexist. The connection with artificial intelligence is also playing an increasingly important role – for instance, in the automated detection of anomalies or in key management in quantum environments.

Quantum cryptography is no longer science fiction. It represents the next logical step in the evolution of IT security. The threat posed by quantum computers is real, the standards exist, and the technologies are ready for deployment. What’s crucial is that companies and institutions begin now to align their communication infrastructure with future requirements. Those who wait too long risk standing on insecure foundations once the technology becomes market ready. Those who act today secure not only their data – but their future viability.

Shipra Kren is a trained IT journalist with many years of experience in both print and online media. Since 2024, she has been part of the eco Association’s PR team.