Actually if you install a llm machine in local, you can already train it with your blogs, writings and such to replicate your writing style, it's not future, it's now already...
I somehow gave up on being secure giving my own data and Id to exchanges and such, simply because the hospital where I've gone has been hacked, all data taken and sold,same for an other clinic, and a betting site so probably my data is well spread in the deep web...
As for how to secure there's a single user, it's a milion dollar question, iris scan I don't like it I'm pretty sure can be faked somehow, check user DNA hashed every time like with saliva would maybe do it, I can hardly see faking saliva
That might be it, a water bottle that checks your dna every now and then and you use it to login to my game to prove you are who you say you are and not running multiple accounts.
Everyone has to drink all the time anyway!
Now if only those bottles were easy to clean! :P
I have a better idea. Every user must have a holozing tattoo on their right arm to play the game. Each tattoo is unique because it has a certain invisible dot matrix. This way it can be guaranteed that only this body with the respective username can play the game. In this way you can combine ZKP with a continuous check of the user as you can check the tattoo every few hours or days using a webcam.
This was just a joke ;)
We got a patent to do here!