It was also my first DL number. Both colleges and VA DMV changed to calculated serial numbers around the same time (late 90s, IIRC).
But, to me, using SSN as a unique serial number feels correct. As somebody else mentioned, that's what it is - a serial number, not a shared secret. "Which John Smith are you?" is very similar to the VIN on a car answering "which Honda Civic?" SSN never proves that you are actually the John Smith you claim.
But, to me, using SSN as a unique serial number feels correct. As somebody else mentioned, that's what it is - a serial number, not a shared secret. "Which John Smith are you?" is very similar to the VIN on a car answering "which Honda Civic?" SSN never proves that you are actually the John Smith you claim.