My records moved from my high school to the district office that oversees all schools in the region. If I appear in person at that district office, no one there would recognize me. They could photograph me, take fingerprints, and take a DNA sample and they still wouldn't know who I am. All they can do is look at a document that says who I am, or ask for a bit of information that only I would know. These things can just as well be done remotely. If we're talking about proof of identity sufficient to satisfy spywork for the Pentagon, for example, a recognized notary public could put their seal on a copy of a gov. issued ID anywhere in the world. Someone could have 100+ people sign their PGP public key attesting to verifying a gov. issued ID. But let's be realistic.