The Other Half of Authentication Is 345 Years Old

Short summary

Medieval scholar Jean Mabillon proved in 1681 that documents can be authenticated by their structure and internal grammar, independent of custody. His key insight—that forgeries reveal themselves at transitions between document parts—applies directly to modern AI deepfakes. Modern PKI validates cryptographic signatures but completely ignores structural authentication, the overlooked half of document verification.

• •Diplomatics authenticates by form and structural coherence, not custody chain—a 17th-century discipline modern security engineering forgot
• •Forgeries fail at transitions between document parts (protocol, text, eschatocol); this principle applies equally to AI-generated and deepfaked content
• •PKI solves cryptographic validation but leaves structural authentication unsolved—the missing mechanism for detecting synthetic documents

Generated with AI, which can make mistakes.