It seems like every organization has their own arbitrary way of assigning numerical identifiers to people. You have a driver’s license number, a social security number, a tax ID, an employee ID, a voter ID, and on and on. Wouldn’t it be nice if everyone just had one single ID? And wouldn’t it be nice if you didn’t have to look this ID up in some kind of database? What if you could figure it out just from your knowledge of a person, even incomplete knowledge? But at the same time, a person’s identifier doesn’t actually reveal any information about them?
Ok, so privacy experts will probably warn about using a common ID for everything, but let’s just ignore them and think about how this could work.