HAPKIDO Handbook: Navigating the Transition to Quantum-Safe PKI

The HAPKIDO handbook guides organisations, policymakers, and PKI operators in navigating the transition to quantum‑safe PKIs by raising awareness of quantum threats and providing actionable insights for migration. Although the transition remains complex and constrained by ongoing standardisation and dependencies, the handbook emphasises that organisations can already take “no‑regrets” steps—such as conducting cryptographic inventories and early risk assessments—to enhance resilience and prepare for migration.

PKIs form the backbone across critical sectors such as government, banking, telecommunications, and healthcare, where their compromise can lead to cascading societal and economic impacts. The handbook establishes that the advent of quantum computing poses a fundamental and inevitable risk to current cryptographic foundations of PKIs, with immediate and long‑term implications, thereby necessitating early preparation and coordinated action. Through its analysis and frameworks—including risk assessment methods, growth models, and migration strategies—the handbook demonstrates that this transition is not merely technical but a complex, multi‑actor transformation hindered by interdependencies, evolving standards, and governance challenges, requiring aligned efforts across organisations and at the ecosystem level, to maintain interoperability and ensure a secure digital future.

This handbook consolidates knowledge derived from five years of multidisciplinary research conducted within the HAPKIDO project.