One area of confusion for new users is understanding what keys are. In user testing practically nobody could figure out what they mean.

One way I think we can make this concept less difficult is just by assigning old terminology next to the new terms.

Instead of just saying "Public key" we can say "Public key (acts as username) or "Public key / username"

Likewise: "Private key / password"

This allows for display names and keeps things on familiar terms although not technically accurate.

Then, as the user signs up, we can slowly introduce concepts to them and educate them on these things to explain how keys actually work.

We can also do a better job of explaining why the user did not need to enter an email or set their own password. For this, we can experiment with micro copy "No emails or passwords, just magic" or some variation that quickly gets to the point that the user will not have to specify either, and briefly explains why, with an option to learn more.

If you have other ideas / better ones, please let me know.