Verifying the creator of a TDF document (e.g. signing it)

[EmberPlot]

Sometimes it's necessary to verify the authenticity of a document. Reading the specs ("data remains protected wherever it travels") it seems that TDF only concerns itself with the protection/encryption of the data and not its authenticity.

• Is there a standardized way to check the provenance of a TDF payload?
• Or is this solely up to the payload itself (e.g. a signed PDF document)?
• Or sign the ZTDF document itself?

Thanks in advance for any insights...

[damorris25]

This is where Assertions come into play. Assertions are basically additional metadata that can be optionally signed and that signature can be used to validate integrity / authenticity.