Seeing is Believing
by Chris on Jul.27, 2004, under General Thoughts and Rants
Spurred by a random comment from a co-worker of mine last night during a post-work wings & beer gathering, I decided today to look into the information on the back of my new Alberta Driver’s Licence. For those of you who haven’t seen one yet (I saw many of them when working as a bouncer, and I just recently got my own) they have a strip on the back that consists of some form of binary encoded information.
My question was, of course, what information.
So, I’ve been phone-tagging this morning, to a few government departments, where at least one of them told me that it’s just what’s on the front of the license, excluding the picture. I’m reasonably sure that this is the case, but it does seem to me that there is too much information on the back for it to be that simple. As near as I can tell, there are 5,824 bits of information stored on the back, or 728 bytes. Even leaving aside compression, and making a conservative estimate as to the size of the data fields, there is about 300 bytes of textual data on the card. Say, a maximum of 400. Now compression can reduce text to sometimes as little as 25% of its size, although one can’t guarantee that compression is being used, since it’s highly likely that the information is encrypted, which usually resists compression.
That being said, what is the rest of the info? Some of it would be checksum data to validate the info on the strip, but I can’t imagine that all of it would be. What information about myself am I carrying around?
The departments I spoke to are reluctant to provide me with real information about it, although I should be receiving a call today to make an appointment with Registries to go in and at least see what they see when my license is scanned. It’s a small step, but I’d like to verify at least that much.
I know that it’s not likely, but if any of my readers has more information about this, or even knows how to go about hunting more down, I’d love to hear it.
July 29th, 2004 on 12:03 am
I’m fairly certain it has your status as a driver on it as well, as when I was pulled over, I had a drivers licence I had lost, and gotten replaced. Its a long story, but they were able to ascertain that I had no tickets and a missing/stolen licence within 2-3 mins. Which, I’m thinking, is less time than it would take to call it in and wait for someone else to run it
July 29th, 2004 on 4:48 am
That’s probably more because the police cruisers have wireless computers that connect to a central database and can look up your information.
A bit of an update to this: Having called Registries and asked that they return my call tuesday, so that I would actually be home, I got a call yesterday (wednesday) while at work asking me to call them. Since I don’t get home until 6PM or later, that doesn’t help me too much, does it?
Faugh. Go government bureaucracies!
July 29th, 2004 on 5:22 pm
Is it possible that the strip only comes in one size, and no more info is stored on it?
July 29th, 2004 on 8:00 pm
As it happens, that’s probably the case. However, the one size is still larger than is necessary for the data it could store, thus leaving it open to storing more than would appear to be there.
July 30th, 2004 on 10:25 pm
Maybe it just says when you’ve been naughty. Naughty boy.
August 1st, 2004 on 10:00 am
When you find out, let me know. Specifically, let me know what it says about you. I am very interested…
And kudos for noticing something like that- I didn’t even really look at the back of my new licence