Hacking dudley
by David Crowe
"Officer, I swear I didn't mean to hack it, but it was either that or be thrown out on the street in skimpy shorts and a thin, sweaty, t-shirt."
I don't know whether to start this story at the end or the beginning. If I start at the end, I have to tell you of my shock when I opened my gym bag and found inside two identical dudley combination locks. How could this be? I only owned one because I get easily confused and two identical locks with different combinations would mean I would be forever getting flustered. Were they breeding, or was someone playing a trick on me? Was it magic, or was it the NSA?
Suddenly, I remembered the beginning of the story (although I didn't realize it at the time). A couple of days before, I had returned to the locker room after my workout and couldn't open my lock. For 15 minutes I swore under my breath, trying the combination I had known by heart for months to no avail. I checked the not-so-secret place I had it written down; it was as I remembered, and still it wouldn't open. I cussed the lock that I assumed must have malfunctioned. Just in case the lock was misbehaving, I was adjusting each number up one, down one, and then, just about when I was ready to give up, the lock opened.
I was glad I hadn't called the locksmith to cut it off. How could I have explained that I was locked out by my own lock? Would the fitness center believe that I wasn't just trying to break in to Mr. Big's locker and steal his stuff? What the heck was wrong with my lock anyway?
But now I realized what had happened. I had picked up someone else's lock and put it on my locker, which is how two got in my gym bag. But how had I opened someone else's lock with my combination?
I started to think about it, and do some investigations. This style of dudley lock has 60 numbers on the ring, so theoretically there are 603 (60 * 60 * 60) combinations - or 216,000. What are the chances of me getting a lock with a combination anywhere close to mine with those odds?
But I've observed that these locks don't require precision. I found that the first number could be off by three and still work - six different numbers would work. So there are effectively only ten possibilities for the first number in the combination. The second number in the triplet is even more permissive. I could be off by five and still open the lock, so there are only six possibilities here. And the third number is also permissive, but it actually doesn't matter. If you get the first two correct (or at least close to correct), you can simply twirl the dial slowly with a little pressure until it opens. So that means the two locks I have really only possess 60 different combinations.
My chances of getting a compatible combination lock were therefore 1 out of 60.
I still wouldn't bet on those odds (I don't bet on any odds, actually), but it's a whole lot more likely than one out of 216,000. I would love to know what the owner of the lock thought when he couldn't find his lock. "What kind of idiot would steal a lock not knowing the combination?" But no locks were reported missing at the gym club (he was perhaps as embarrassed as me), so I had no chance of finding him and returning it. Now I am the proud owner of two locks that can be opened with the same combination.
The normal disclaimer implies. Use this to get yourself out of trouble, not to get yourself into trouble.
I'm not a lock picker; the only thing I'd picked before was my nose. It's probable that experts know even more tricks with these locks, in which case they are pretty useless. Good for protecting clothes at the gym club, but don't fill your locker with gold bars and expect them to be there when you get back.