The 2008 innovation that allows a next paradigm for proof-of-unique-person

In 2008 Bryan Ford invented Pseudonym Parties (link), an innovation that allowed a new way to organize proof-of-unique-person. Rather than relying on a hierarchy that verifies everyone (which is also a perfectly valid solution and the one that has been used historically, incl. with biometrics in nation-state identities like passports these days), his idea was to rely on doing a verification event for everyone in the world at the exact same time. This was a true innovation that hinted at a new way of solving a very old problem (a problem that has been solved historically too, but this was a potential new way of solving it). Today in "crypto" most "proof-of-unique-person" are either using the legacy solution (like "WorldID" from OpenAI that is a central entity that verifies everyone and that would need to be overseen in same way as in traditional central entity verifying everyone) or are just role playing games with no actual game theory behind them (such as ideas that a web-of-trust could magically provide central proof-of-unique-person, a fiction as such are trivially attacked and cannot be secure). Then, there is a couple of projects that have spun from Bryan Ford's "everyone at the exact same time" idea. Mainly there are two. One is not a serious idea game theoretically, it suggests computer puzzles that would be impossible for a person to solve multiple of at the same time (this is not serious idea it is a bit silly). The other is to simply let people verify other people at the exact same time but to do it over video (and the logical way to do that is 1-on-1 with a "dispute" mechanism that subordinates both people under a random other pair, plus the same 2-on-1 mechanism when joining without being verified the previous month).

Why not just do Ford's Pseudonym Parties? It has the fake region problem, anyone can pretend to be a trillion people in the middle of the Pacific Ocean. One project, Encointer, tried to resolve that by making the proofs only valid within a group but that defeats the entire purpose (and essentially becomes a central verifier again, which as I have said is the only other solution historically).

The entire family of "everyone at the exact same time" is generally a-personal and anonymous IDs and ephemeral (they are valid one period and they can be laundered each period so they become untraceable between periods). They are also generally very transaction heavy, as each period needs to do a few transactions per person in the entire world, thus multiples of 8 billion per period (for monthly periods this reaches roughly 100k transactions per second). So they are not practically scalable right now, they are something to plan for in the long term.

The "let's just use a web-of-trust" fairytale appeals to many but it will always run into the obvious game theory attack vectors and gradually introduce "ducktape" to try and fix that and this "ducktape" will always end up taking the shape of a central verifier... People would do better to embrace the legacy solution that already exists instead of trying to desperately chase "web-of-trust" fantasy, and to then also think soberly about a potential next paradigm.

This said then, the ideal next paradigm becomes what is formally described since many years and fully implemented since many years (but not practically scalable until a few more generations of digital ledger technology so at least 10 more years...) and that was originally in 2015 called "virtual pseudonym parties".