Unique Identifier
As more and more things are moving online, two problems became apparent to our collective consciousness: How do you know someone is really a person? How do you know someone is who they say they are? Initially, the “person” thing wasn’t a big issue, the internet was used for low-stake amicable activities, and impersonation, bots, and alternative accounts weren’t a big deal. As for the second issue, well, we used usernames and passwords.