MDL — Markdown Logged: An Open Trust Layer for Text (v1.1)
László Tatai · Zenodo (CERN European Organization for Nuclear Research) · 2026
MDL (Markdown Logged) is a lightweight, cryptographically verifiable document format built on Markdown. Any .md file can be wrapped in a four-layer proof architecture without breaking human readability or requiring external infrastructure. Proof layers: SHA-256 hash (L1) · local entropy (L2) · real-world market anchor via Yahoo Finance (L3) · Ed25519 digital signature (L4). Core principle: a document is not trusted because it cannot be changed, but because any change is provably visible. This release contains the formal MDL v1.1 specification, Python implementation (CLI + modules), and example documents. The specification is published as its own .mdl file — MDL verifies itself. MDL is the reference implementation of Reality Proof — a method for binding digital content to time, origin, and real-world state.