3-D Printed Skeleton Keys can Pick High-Security Locks

Engineers Jos Weyers and Christian Holler can 3-D print a plastic or metal key that opens high-security locks in seconds.

The original key isn't needed. The trick is to 3-D print a "bump" key, which resembles a normal key but can open millions of locks with a carefully practiced rap on its head with a hammer.

Using software they created called Photobump, they say it's now possible to easily bump open a wide range of locks using keys based on photographs of the locks' keyholes.

Even without a high-quality 3-D printer, those specialized bump keys can be mail-ordered from 3-D printing services like Shapeways or i.Materialise which have no restrictions on printing keys.

"All anyone needs to open locks previously considered unbumpable is software, a picture of the lock's keyhole and the keyhole's depth," says Weyers, a competitive lockpicker and security consultant.

"You don't need much more to make a bump key," Weyers told an audience at the Hackers On Planet Earth conference, where he first hinted at the key printing software last month. "Basically, if I can see your keyhole, there's an app for that."

Many lock makers carefully trademark or patent their key blank designs and prevent them from being sold to anyone outside a small group of verified customers. But with the advent of 3D printing, those restrictions can't stop lockpickers from 3D printing their own blanks and filing them into bump keys.

A photo of a keyhole alone isn't quite enough to print one of Weyers' or Holler's bump keys. They also need information about the position of each pin in a target lock. But Holler says that information is easily found in widely available key-cutting software.

Weyers says he can derive it even more easily by sticking any thin tool into the keyhole, feeling for the pins and marking their depth to measure how deep in the lock's cylinder the pins are located.

Those measurements and the key's cross-sectional shape derived from a photo are fed into the Photobump desktop software to create a printable 3-D CAD model.

Weyers and Holler told Wired that they aren't trying to teach thieves a new trick for breaking into high-security facilities; instead, they want to warn lock makers about the possibility of 3-D printable bump keys so they might defend against it.