Requirements analysis for hybrid quantum-safe electronic document signatures

The current digital society in which we live heavily relies on securecommunications and digital trust services. These are dominantly achieved through Public Key Infrastructures (PKIs), for which the underlying cryptographic implementation is expected to become vulnerable against quantum-capable adversaries in the coming years. The HAPKIDO project studies how to realise the transition of services and systems towards a hybrid state of PKIs which encompasses quantum-safe cryptography next to the classical component. This is a complex problem with challenges in areas ranging from technology governance, to cryptography, and systems integration. In this context, the current deliverable focuses on the system integration challenges, and analyses the requirements a hybrid PKI system must satisfy, and how the transition will impact these systems with respect to computational performance.