> The same key, in every app, for every recipient. Not assignable to anyone else, not revocable, not subject to suspension. Yours forever.
This is impractical and the opposite of what we want. It's a required ID to use the internet, monitored by governments, tracked by corporations, and forever unchanging.
What we need is a system that allows people to easily create new IDs, that updates contacts that people choose. Think of a contact book that sends new keys to all contacts on every change. (Contacts would need to be always online.) It could update the key used on a website or not, depending on the users choice.
Breaking tracking and required IDs means flux and churn.
> What we need is a system that allows people to easily create new IDs, that updates contacts that people choose.
> Contacts would need to be always online.
That also sounds impractical.
> It's a required ID to use the internet
How does any of that follow? Having a reusable self-sovereign ID format for those scenarios where people want to share it is very different from having an authority-issued ID format that's mandatory for some interaction.
As a concrete example: I have an iMessage (CKV), Signal, WhatsApp, and GPG identity key, but I don't need to provide any of them when ordering pizza online. But what I can't do is choosing to use the same key for my same number on both e.g. Signal and iMessage to make it easier for people to switch between messengers without having to re-verify me.
A hypothetical shared key format would fix that, but would (hopefully!) still allow me to create multiple keys/identities for multiple contexts, and to not provide any persistent identity when it's not necessary.
If the ID is permanent then governments will require it, because they can. If it has attestations or endorsements, governments will require a government endorsement. Think about what China, Iran or Russia would do with a permanent ID being a standard. The US, England and the EU are not immune to the same impulses.
Always online is no different than an email account or website, and the rate of change would be, at least, minutes not seconds.