>In the US, we have social security numbers. Is it true that Canada uses >driver's license numbers for unique ID numbers?

We have nine-digit Social Insurance numbers, in the format 999 999 999.
You have to apply for a Social Insurance number - most people get them in high school when they first get a job.

I was once faced with writing a program to enumerate a large group of people, half of whom didn't have Social Insurance numbers, the other half of whom had two, so they could collect welfare in two provinces.