Options for Metadata Binding

When it comes to managing opt-out declarations for TDM in a machine-readable way, in principle, two different approaches are discussed:

1. Location or domain-based metadata binding: rightsholder preferences for web-published content are included in robots.txt-file or in HTML/HTTP metadata of the domain, e.g. Robots.txt, TDMrep;

2. Asset-Based metadata binding: metadata is embedded directly into the media file, e.g. C2PA.org (Hard-Binding) or metadata is provided in an external (sidecar) file and linked to the ISCC code (Soft-Binding)

Why do we need Soft-Binding?

• Embedded metadata is removed from the media file.

• Content is altered or manipulated, compressed or converted into a different file format – and the method is based on cryptographic hashing.

• When content is already distributed, shared and part of training sets, metadata cannot be embedded.

• Content is shared on websites beyond the rightsholder's control, e.g. on social media, so a domain-based approach cannot be applied.

• A lot of content is not publicly accessible on web domains.

• Watermarks or steganographic data can be removed from media files.