self

I already successfully used EU digital signatures through lex [1], but neither openpassport [2] not withpersona / linkedin [3] supports EU's new (2019+) identity cards, only passports. [1] https://lex.community/ [2] https://github.com/zk-passport/openpassport/issues/126 [3] https://www.linkedin.com/help/linkedin/answer/a1631613

I didn't mention hashes anywhere in this thread, you were the one claiming you can prove someone's age just based on a hash of it (and still haven't shown how other than breaking the hash with a rainbow table). I posted this earlier (and it's in the article...) but will reiterate again: ZK proofs are used when the prover (server) and verifier (client) don't trust each other and don't want to give each other data on each other. If you trust the server you can just give it a copy of your passport, if the server trusts the client they can just show a checkbox asking if they're old enough. I linked to a working library earlier, it's here https://github.com/zk-passport/openpassport

What do you mean scoped to a particular proof? There are different proof types like there are different hashing algorithms, they can all prove any data just like sha256 and md5 can hash any data. How do you verify the password meets certain requirements sever side without getting that user data? Client side input can't always be trusted as anyone can modify that regex check. Here's a project doing passport verification for services without needing to send them a photo of your passport: https://github.com/zk-passport/openpassport With something like TLS notary you can prove anything signed by a https certificate, so you can prove there are enough funds in your bank to get a mortgage without revealing how much money you have.

ZKPs have only become cheap and easy enough to do in the last few years, so of course Goldman Sachs doesn't use them yet. They'll be using them in a decade, for now look at startups. https://github.com/zk-passport/openpassport is one that is working today, worldcoin ID verification is another.