New technology for high-security locks
KEYS have been around for a long time. The earliest, made from wood, date back 4,000 years, to the ancient Egyptians. The Romans improved them a bit by making them from metal. But there, more or less, they have stayed. Electronic card-keys aside, a key is still, basically, a piece of metal sporting a series of grooves, teeth and indentations which, when inserted into a keyway, line up to move pins and levers to lock or unlock a mechanism.
Such keys are made with conventional manufacturing techniques, such as cutting and stamping. But now there is a new way, in the form of 3D printing, to craft metal objects. And keys are about to succumb to it, to the great benefit of keyholders.
A 3D printer works by melting together layers of material that are added successively to the object being created. It can thus make something from the inside out, as it were, by printing intricate internal features and then covering them with a solid layer. Features shielded from view are extremely difficult to copy, let alone reproduce using normal machine tools. What better way to reinvent the key, reckoned Alejandro Ojeda, a mechanical engineer who at the time was studying at the Swiss Federal Institute of Technology, in Zurich, than to 3D-print it in this way.
What prompted his interest is how simple it is to copy most keys: a few minutes at a local key shop will usually suffice. And copying is getting easier. It is now possible to take a picture of a key with a smartphone and turn the image into a computer file that can be used to make a replica with the aid of a cheap, hobbyist 3D printer. The resulting duplicate will probably be printed in plastic, and thus lack durability. But it is likely to be good enough to work at least once—and once might be enough.
Dr Ojeda’s answer is the Stealth Key (pictured). This is printed in titanium, one of the toughest of metals. Its teeth are hidden under a pair of narrow ledges, making it unscannable. But when inserted into the lock the teeth can operate the mechanism.