As explained in https://lemmy.amxl.com/post/709344, government issued identities are an essential building block on top of which uniquonyms are created.

However, there is a diverse range of governments out there, and they all do things differently.

The simplest would be if they all acted like a Certificate Authority - you prove your ID to them, and give them your public key, and they give you a certificate linking your public key to the unique ID. You then publish a document linking your ID number to your public key and a hash of a secret only you know, and including the certificate - this establishes your public real world identity. Later, you publish a message establishing your pseudonym as a hash of the secret and the namespace, with a zero-knowledge proof that a publicly disclosed identity with a valid government certificate exists somewhere in a particular tree, and that the secret matches.

However, most governments do not provide this Certificate Authority service unfortunately, and when they do, access to it is often heavily gated behind barriers to entry on who can use it and for what purpose. It also often has a fee, which would deter uptake. There are some private businesses which specialise in verifying government identities and issuing certificates - but this again has a fee, and introduces an additional trusted third party.

Many governments, however, have some form of online login system and portal (for government services) where people can log in using HTTPS (specifically generally HTTP over TLS1.3 these days), and between the contents of the request and the response, that will be enough to identify an individual uniquely. Leveraging this (combined with a per-country module system for understanding what needs to be proven about the HTTP request and response) would solve the needs for Uniquonyms. This requires a way to prove to others that a TLS1.3 transcript is genuine - which is a very difficult problem - and a topic for a future post.