It’s easy to guess your keypad code

The world around us is replete with keypad locks. They’re a brilliant form of access control because they’re easy to use and they don’t require you to dish out endless amounts of keys to all the staff or users of the building.

They do what they’re supposed to quite well, too, except when they’re mis-used.

Who would mis-use a keypad lock? Are we talking vandals? No, we’re actually talking about the normal everyday people who use the lock.

What makes keypads insecure?

The whole point of the keypad is that only the right people know the code. That’s the lock’s only line of defence. If the wrong person knows the code, the whole thing falls apart.

The thing is that the code is often super easy to guess or work out. All it takes is a couple of buttons to be dirty from too much being pressed.

For instance, a typical code has four digits and is a year in the twentieth century. Years are easy to remember, especially important years like 1945. If you can see a smudge on digits 4 and 5, you could take a stab at the code by assuming the missing digits are 1 and 9.

It’s worse in historical buildings

Imagine you’re in a National Trust property or a museum dedicated to a particular historical event. There’s a good chance that the code in, say, a building dedicated to the Duke of Wellington, who beat Napoleon at Waterloo in 1815, would set its codes to 1815.

“Surely not,” I hear you say. Though it’s very likely all the same. Instead of remembering a sequence of four random numbers—which, let’s face it, isn’t that hard—many people are willing to sacrifice the security of their building by choosing years in the twentieth century or a really obvious year as the code.

If you care about your security, please do these things for me. It will do you a world of good:

• Keep the keypad clean so that it’s hard to guess any numbers in the code.
• Choose four truly random numbers for the code, ideally avoiding the number 1 (since any miscreant will assume that 1 is part of the code). Keep the code nice and meaningless.
• Change the code every so often so that all the buttons wear out evenly. This will increase the longevity of the lock as well as making life harder for intruders.