Post-Quantum Cryptography

Post-Quantum Cryptography (PQC) refers to cryptographic methods designed to remain secure even against attacks from future quantum computers. Its primary objective is to ensure the long-term protection of digital data and infrastructures while making systems resilient to future technological developments. As a result, the concept of crypto-agility is already gaining importance today: organizations must design their systems in a way that allows for the flexible integration of new, quantum-resistant algorithms.

What is Post-Quantum Cryptography?

Post-Quantum Cryptography (PQC) encompasses cryptographic techniques that are resistant to attacks by future quantum computers. Traditional public-key systems such as RSA or elliptic curve cryptography rely on mathematical problems that could be efficiently solved by sufficiently powerful quantum computers.

PQC therefore adopts alternative mathematical approaches—such as lattice-based, hash-based, or code-based cryptography—for which no practical quantum attacks are currently known.

Why is PQC Relevant?

Although large-scale quantum computers are still under development, there is already a clear need for action today. In the context of “harvest now, decrypt later” scenarios, encrypted data may be collected now and decrypted at a later stage once adequate computational capabilities become available.

This particularly affects information requiring long-term protection as well as critical digital infrastructures—such as digital identities, electronic signatures, and government services. Early migration to quantum-resistant cryptography is therefore a key component of sustainable IT security strategies. At the same time, crypto-agility enables organizations to respond flexibly to future developments and integrate new cryptographic methods without the need for extensive system overhauls.

When Will PQC Become the Standard?

International standardization efforts—particularly those led by the U.S. National Institute of Standards and Technology (NIST)—are already well advanced. Initial PQC algorithms have been selected and are gradually being incorporated into standards and products.

At the European level, a clear framework for the transition has also been established. In 2025, the European Commission published an implementation roadmap outlining the following milestones:

• Initiation of migration by the end of 2026 at the latest
• Securing critical infrastructures by 2030 at the latest
• Broad adoption across additional systems by 2035

This clearly indicates that the transition to quantum-resistant cryptography is not a distant future concern, but an ongoing transformation process at the European level. In the coming years, therefore, a gradual but widespread adoption is to be expected—particularly in security-critical areas and digital infrastructures.

Our Contribution at A-Trust

As a qualified trust service provider, A-Trust is proactively engaging with post-quantum cryptography to ensure that its solutions remain sustainable and future-proof.

We continuously evaluate emerging cryptographic methods and their integration into existing systems—particularly in the fields of digital identity and signature solutions. Our goal is to maintain the highest security standards even in the age of quantum computing and to provide our customers with trustworthy digital services in the long term.