There are relatively few ways of identifying an individual. When you are born, your birth is registered at a government records office, and the office issues a birth certificate to your parents. A few years later, your parents enroll you in school, presenting the birth certificate so that the school can issue you a school identity card. Still later, you submit the birth certificate and a photo to get a passport or a national identity card. In a similar fashion, each of us receives many other authentication numbers and cards throughout life.
This life-long process starts with a baby’s birth certificate. But the baby’s physical description (height, weight, even hair color) will change significantly in just months. The birth certificate may contain the baby’s fingerprints, but matching a poorly taken fingerprint of a newborn to that of an adult is challenging at best.
Fortunately, in most settings it is acceptable to settle for weak authentication for individuals: A friend who has known you since childhood, a schoolteacher, neighbors, and coworkers can support a claim of identity.