Convenience and Security do not go hand in hand. Convenience is having a single universal number for identifying and tracking a person. Security demands that we have multiple numbers for each type of information source and no direct links between them. Unfortunately any single number that is linked to all of a person data, no matter how many bits associated with that number, is a point of vulnerability. If you have a sequence of numbers and I manage to break one of them, I should only be able to access one part of your information not use it to access all.

Recently my mother had charges made to all of her credit cards, one of which she hasn't used in over a year. She checked they were all in the drawer where she always kept them (she only carries one). This indicates a hack and a pretty good one, since the one card she never uses, has never been used in an online transaction. Visa and Mastercard, told her point blank they had no idea what to do. They just sold her credit protection and went on their merry way.