Your key. You own this.

Your phone is about to generate a secret it never tells anyone, not even Semios. The key is the proof you exist here. It lives in this device and nowhere else.

What you just did, plain: your browser made a cryptographic keypair on this device. The private half is sealed in the browser's secure crypto context and cannot be exported, copied, or synced to a vendor. The public half is the address others sign messages to. Delete this site's data on this device, and the key is gone.