> issue your own tokens
I mean, you can. It's like with TLS certificates. The standard is there. The code is there. You can issue your own.
The question is, who will trust you?
It is not at all like TLS. With TLS you at least can get your own certificate signed by an official CA, and use that private key on whatever system you want.
It is not at all like TLS. With TLS you at least can get your own certificate signed by an official CA, and use that private key on whatever system you want.