But it is not such a good idea if the bad guys can reproduce the keys with a 3D printer. This has already been causing problems regarding cheap handcuffs for some years, but last year a German hacker demonstrated that it also works for handcuffs by top-quality brands who did their very best to make sure that only the police had the keys.
And what about ordinary house keys? The hacker needed the original keys to the handcuffs to copy them, but you can actually print a key to a front door using only a few photographs made with your phone. In 2008, an American professor demonstrated how he could make a useable key from a photograph he had made using a telephoto lens at a distance of more than sixty metres.
In August, students at the Massachusetts Institute of Technology announced that they could replicate keys by the top brand Schlage Primus which the makers presumed could not be duplicated. The students predict that perhaps the traditional key with teeth might disappear in the era of 3D printing.