Security through QKD
It is common sense that quantum computers will someday break classical public key cryptography based on the problem of factorization or discrete logarithm. Quantum cryptography addresses this issue and provides robust methods against such problems. One key element is quantum key distribution (QKD). QKD ensures the secure distribution of a common key between parties based on assumptions of quantum mechanics, but still relies on classical building blocks like information-theoretical secure authentication mechanisms. But quantum cryptography and its hardware-based approaches itself offer new challenges like new classes of side-channel and fault-injection attacks compared to classical solutions.

Hybrid Key Generation
With that knowledge in mind, several approaches evolve. Hard work is invested into the finding and development of possibilities to avoid side-channel and implementation attacks. One alternative setup is the combination of quantum key distribution with key generation based on classical cryptography (hybrid method). It solves the major issue of breaking classical key distribution methods with quantum computers and contributes with security-evaluated implementations and the smaller attack surface to side-channel attacks to the confidentiality of the transferred data. Once the hybrid key is generated, this approach also adds the performance advantages of classical symmetric cryptography and offers the possibility of using existing devices already implementing classical well-understood and evaluated protocols.

Rohde & Schwarz Cybersecurity is a leading IT security company that protects digital assets of companies and public institutions around the world against cyberattacks. The IT security expert provides innovative data protection solutions for cloud environments, advanced security for websites, web applications and web services as well as network encryption, desktop and mobile security. To prevent cyberattacks proactively, the trusted security solutions are developed according to the security-by-design approach.