In principle, any digital artifact may be digitally signed, just like web pages are (using CA's). That way, you can set up a chain of trust, to track where som

In principle, any digital artifact may be digitally signed, just like web pages are (using CA's). That way, you can set up a chain of trust, to track where some information is coming from. This works as long as there is at least a top level signature provider that is uncorrupted. That will be hard in authoritarian societies and maybe even harder in radically polarized societies. Imagine a world where the CPP, DNC and GOP (and others) each controlled their own CA's, and had the ability to present a fake view of reality to their supporters.