# Why Document Verification Needs Layers

Structure, integrity, signature, identity, time and current status answer different questions and should never collapse into one green badge.

## Verification boundary

Structure, exact-state integrity, signature validity, signer identity, trusted time and current status are separate questions. Integrity does not prove content truth. A claimed identity inside a document is not independent identity evidence.

Canonical source: https://universaldocument.org/verify/articles/why-verification-layers