So I stumbled upon the weirdest lock I’ve ever seen this week. We’ve talked a bit before about how a standard lock will work. It’s a little puzzle that requires a key of the right shape to put all the pieces in place and allow entry. That said, pretty much anyone can learn to pick those locks with the right tools and a lot of patience. But I’ve found a lock which will thwart picking simply because it’s designed for a key unlike any other.


Also known as chain keys, flex keys, and a number of other names, the soft key is more or less exactly what you’re picturing. Whereas a regular key is a straight piece of metal, soft keys are made like watchbands so they can roll and bend.

Understandably, these keys are a bit fragile, so they need some extra hardware. The keys are designed with a casing around them so you can “inject” the key into the lock.

Cool, sure, but ostensibly impractical. You’re probably asking why someone would want such a weird key.



Diagram of Soft Key
They’d want it to pair with a really weird lock. The patents for it are available on Google for you to peruse, but I’ll save you the trouble.

Here’s a diagram of the inside of the lock. It shares some basic similarities with your average lock, but the key path is serpentine.

Only a soft key can pass through to open the lock. This is why it may well be unpickable. A typical lock  has a straight path, so you just have to fiddle with the pins until you get it to open. But this lock won’t take picks because there’s no way to know how it’ll bend, and even then your standard picks can’t meet the shape. As an added precaution, you can see there are some branch paths in there, so even if you do manage to curve a pick through there, you might hit a dead end.



Nine times out of ten, it probably is. I’d never say any lock was unpickable, because there’s always a way through. Some locks just require a less-subtle approach. Like a power drill, for example. If you want to get your own to play around with, it’s not gonna be easy. Sometime they pop up on ebay, but it’s rare and they aren’t cheap.

In the meantime, you’ll just have to join the rest of us in living vicariously through the people who have managed to get their hands on them.