Post-Quantum Discovery as a Governance Capability: Evidence-Based Cryptographic Visibility and Exposure Prioritisation in a Critical Service Provider

TL;DR

This paper demonstrates how a large European critical service provider used cryptographic discovery and exposure management to enhance governance and prioritize PQC migration efforts amid complex dependencies.

Contribution

It introduces a structured discovery and exposure approach as a governance capability to improve PQC readiness and cryptographic visibility in critical infrastructure.

Findings

Cryptographic visibility is crucial for PQC readiness.

Distributed ownership and dependency challenges hinder migration.

Structured exposure registers enable better prioritization.

Abstract

Post Quantum Cryptography (PQC) readiness is increasingly constrained not by algorithm availability, but by cryptographic visibility, dependency complexity, and fragmented governance. This paper presents an anonymised case study of a large European critical service provider that initiated PQC readiness through a discovery first strategy, utilizing tool supported cryptographic inventorying to establish an evidence based baseline prior to migration planning. The discovery phase revealed systemic challenges, including distributed cryptographic ownership, uneven evidence quality across legacy and modern environments, and high dependency on third party cryptographic roadmaps. To operationalise these findings, the organisation introduced a structured exposure register that enabled prioritisation based on asset criticality, confidentiality longevity, and migration feasibility. We argue that PQC discovery should be understood as a governance capability that stabilises organisational knowledge and converts cryptographic uncertainty into measurable accountability, supporting risk based decision making and ecosystem coordination. The results contribute actionable lessons for institutions pursuing crypto-agility and resilience under post quantum harvest now, decrypt later threat models.