Authentication systems typically fall into two categories: deterministic systems that resolve identity with certainty and probabilistic systems that rely on interpretation or behavioral signals. Understanding the difference between these models is critical when evaluating technologies used for product authentication, infrastructure verification, and security-sensitive environments.

Traditional QR codes were built for connectivity, not security. Because identity is exposed in the image, copying the code reproduces trust. At scale, this creates structural verification risk. Deterministic identity verification replaces readable or link-based models with protocol-level resolution, ensuring each scan returns a binary verdict and copying produces anomaly, not legitimacy.