Mosca's Inequality is a three-variable test for whether your organization has missed the window to migrate to post-quantum cryptography. For most teams with data that needs to stay secret for a decade or more, the inequality has already been violated. Here's the framework, one worked example, and what to do next.

HNDL is the practice of capturing today's encrypted data and decrypting it once quantum computers exist. This guide explains why security-conscious developers need to start their PQC migration in 2026, how Mosca's inequality maps HNDL exposure, and where to begin.