What is OSDF
OSDF (Open Secure Document Format) is an open specification for documents that carry their own trust. Where a traditional file relies on the system around it - the network, the portal, the email gateway - an OSDF package carries cryptographic integrity, verifiable provenance, and access policy inside the file itself.
Trust that travels with the file.
The core idea
A document should be able to answer three questions on its own, anywhere it travels - online or fully disconnected:
- Is it safe to open? The format is passive by default: no scripts, macros, or auto-fetched content.
- Has it been tampered with? A signed manifest and hash-linked revisions make any modification detectable.
- Who is allowed to read it? Confidential payloads are encrypted and released only through an authorized access decision.
What OSDF is not
- It is not a DRM black box. The specification, schemas, and test vectors are open.
- It is not a replacement for PDF. OSDF interoperates with PDF and can embed a frozen PDF/A rendition for portability.
- It is not a blockchain. Provenance uses signed Merkle logs with witnesses, not a public chain or token.
How it fits together
| Layer | Responsibility |
|---|---|
| Container | Strict, constrained ZIP with a declared object table |
| Manifest | SHA-256 digests for every object, plus signatures |
| Revisions | Hash-linked, canonicalized revision history |
| Transparency | Signed Merkle log, inclusion + consistency proofs |
| Access | Envelope-encrypted payloads released by policy |