How can embedded and networked systems remain secure over long life cycles in the face of changing threats such as powerful quantum computers? In the DFG project Holistic Security Solutions for Software-Hardware Implementations (H3SI), researchers from the Max Planck Institute for Security and Privacy, RheinMain University of Applied Sciences, Darmstadt University of Applied Sciences and Academia Sinica in Taiwan are tackling the challenge of long-term security by developing verifiable, efficient and adaptable cryptographic solutions with a special focus on embedded systems.

Embedded systems are a key driver of digitalisation in industry and infrastructure, but are often resource-limited and in use for decades. Their security depends crucially on the correct implementation and utilisation of cryptographic algorithms and communication protocols. Even strong algorithms can be rendered ineffective by implementation errors, incorrect embedding in protocols or side-channel attacks. However, many approaches statically determine the cryptographic algorithms and are only able to take necessary updates into account to a limited extent, for example if algorithms become insecure as a result of advances in cryptanalysis or the capabilities of quantum computers.

The aim of H3SI is to improve the long-term security of embedded systems through a holistic approach that considers cryptographic implementations, communication protocols and system-wide security requirements together. A central focus is on post-quantum cryptography (PQC), which is expected to replace many of the cryptographic methods used today, but poses significant challenges in terms of efficiency and integration, especially in embedded environments.

As part of the project, we are developing a secure system design model that explicitly considers future changes to cryptographic algorithms and protocols and their impact on security, performance and energy consumption. This model is complemented by runtime policies and verification mechanisms to ensure the correct use of cryptographic primitives. Furthermore, we formally design and verify long-term secure and crypto-agile communication protocols, including migration and fail-safe mechanisms for the transition from classical to post-quantum cryptography.

Finally, H3SI investigates correct, secure and efficient implementations of cryptographic algorithms with a strong focus on post-quantum methods. Using modern verification tools, the project aims to provide formally verified implementations that are resistant to side-channel attacks and suitable for integration into secure embedded systems.