Gravatar uses something like this, which they call identicons.[1] I haven't come across the idea used anywhere else. I'd think it'd have some place in the cryptocurrency world.

[1] https://en.wikipedia.org/wiki/Identicon

Yes. Same core idea as Identicon although original intent behind that was to use it for visual distinction, not recognition.

I think Lotus Notes also used to something similar when you typed in your password. Its been a while (thankfully) since I used it though.

when I read the title I thought of qr codes but didn't see them scrolling through, curious now though