---
title: "Signed semantic metadata — Glossary | LLMind"
description: "Metadata describing a file's meaning, cryptographically signed so consumers can verify integrity."
url: https://llmind.org/glossary/signed-semantic-metadata/
source_format: html
---
[← Glossary](https://llmind.org/glossary/)

# Signed semantic metadata

**Metadata describing a file's meaning, cryptographically signed so consumers can verify integrity.**

Signed semantic metadata combines two ideas: semantic (describing meaning) and signed (cryptographically verifiable). The metadata describes what a file is — its description, entities, structure, transcription — not where it came from or who edited it. The signature proves that the metadata hasn't been modified since the signer wrote it. LLMind's core offering is signed semantic metadata: it lets AI systems trust file descriptions without relying on external databases or APIs.

## Two adjectives, one idea

Semantic metadata answers "what is this file about?" — a description, a list of people mentioned, a table of contents. Signed means every byte is protected by a cryptographic signature. Together, they let an LLM read a file's description and trust it: the description came from a known source and hasn't been altered. Without the signature, a description is just a claim. With it, it's a verified fact.

## Layered signing

LRFS signs each semantic layer independently — description, entities, structure, transcription, lineage. A consumer can trust the description without trusting the entities. An LLM can verify the transcription came from a trusted OCR system without vouching for the human-written summary. This granular trust model lets different tools and teams own different layers while maintaining overall integrity.

## Related terms

-   [Tamper-evident metadata](https://llmind.org/glossary/tamper-evident-metadata/)
-   [HMAC-SHA256](https://llmind.org/glossary/hmac-sha256/)
-   [Semantic layer for files](https://llmind.org/glossary/semantic-layer-files/)

## See also

-   [Security page](https://llmind.org/security/)
-   [Signing scheme](https://llmind.org/spec/signing-scheme/)
-   [Learn](https://llmind.org/learn/)