Third-party timestamping

It answers a question signatures do not settle. A signature proves origin and integrity; it does not prove the date, since the issuer controls their own clock.

The mechanism sends a digest — never the document — to an authority that countersigns it with its own clock. The content therefore never leaves the organization.

An honest distinction must be kept between a document merely published and one genuinely countersigned by an authority. Conflating the two borrows credibility that was not earned.