A cryptographic inventory is a structured catalogue of all cryptographic implementations in your organization. It records where which algorithms, key lengths, and certificates are deployed — from TLS configurations to disk encryption to signature methods. The inventory complements the cryptographic policy: while the policy defines target requirements, the inventory shows the current state. In your ISMS, the inventory lets you systematically identify outdated algorithms and plan their migration. In the context of post-quantum cryptography, an up-to-date cryptographic inventory becomes a prerequisite for an orderly transition.