OTF Content Provenance
Sign, embed, and verify C2PA manifests in OTF files (.otf)
What Is OTF Provenance?
OpenType Font format, the industry standard for cross-platform typography. OTF provenance protects font intellectual property and licensing.
With Encypher, OTF files carry their own cryptographic proof of origin. A C2PA manifest is embedded directly into the file, recording who created it, when, and whether it has been modified. Anyone can verify a signed OTF file for free, without authentication.
How C2PA Manifests Are Embedded in OTF Files
- MIME Type
- font/otf
- File Extensions
- .otf
- Embedding Method
- Custom JUMBF/COSE structural embedding in OpenType font tables
- Container Type
- Custom JUMBF/COSE
- Verification Pipeline
- Custom JUMBF/COSE structural verification (Encypher implementation)
The C2PA manifest contains a JUMBF (JPEG Universal Metadata Box Format) store with COSE-signed claims. For OTF files, the manifest is stored using custom jumbf/cose structural embedding in opentype font tables. The signing process does not alter the font content itself. The manifest is metadata, not a modification of the content.
Use Cases for OTF Provenance
- Type foundries
- Font licensing
- Brand typography
- Publishing fonts
How to Sign OTF Content with Encypher
OTF signing is available at the Enterprise tier through the unified /sign/media API endpoint. Upload your OTF file, and the API returns a signed copy with an embedded C2PA manifest.
curl -X POST https://api.encypher.com/api/v1/sign/media \ -H "Authorization: Bearer YOUR_API_KEY" \ -F "file=@example.otf" \ -F "title=My OTF Content" \ -F "action=c2pa.created" \ -o signed.otf
Verify OTF Provenance (Free)
Verification is free and requires no authentication. Any third party can verify a signed OTF file to confirm its origin, check for tampering, and read the embedded rights information.