Index
- The foundation: Why cryptography is indispensable
- The turning point: How quantum logic reverses the one-way streets of mathematics
- Strategic timing
- The invisible archive: Why “harvest now, decrypt later” is already happening
- The solution: post-quantum cryptography (PQC)
- Why now is the right time to act
- A roadmap to quantum resilience
- How to put PQC into practice today
- Sessions
- Post-quantum resilience as the foundation of digital sovereignty
In cybersecurity, there are moments that change everything. Although we are currently investing heavily in defending against current attacks — according to Bitkom, the IT security market is expected to grow by around 10% (link in German) — a technological evolution is unfolding in the background that will redefine our understanding of security: quantum computing.
This is not a hardware crisis, but rather an opportunity to ensure the future of digital trust. It is not just about protecting servers anymore; it is about taking the mathematics that underpin our entire economy to a new level.
The foundation: Why cryptography is indispensable
To understand why quantum computers pose such a fundamental threat, it is important to examine how digital trust is established today. Almost every online interaction — from logging into the cloud and conducting online banking transactions to sending encrypted messaging — relies on asymmetric cryptography, such as RSA and ECC.
The principle behind this cryptography is the “one-way function”: A mathematical problem that is easy to compute in one direction but practically impossible to reverse.
- RSA (prime factorization): Multiplying two large prime numbers is easy. However, reversing the result to identify the original primes is computationally infeasible for classical computers. This is the foundation of TLS certificates and secure email.
- ECC (Elliptic Curve Cryptography): It uses complex curve mathematics to achieve the same level of security as RSA with much shorter keys, enabling secure communication on resource-constrained devices such as smartphones.
- PKI (Public Key Infrastructure): It is the organizational backbone that ensures a public key truly belongs to a trusted entity (e.g., your bank). PKI is the internet's digital identity system.
As long as these mathematical problems remain unsolvable, our digital identities are secure. However, quantum technology intervenes here.


