The security of high-end handcuffs depends on a detainee not having access to certain small, precisely-shaped objects. In the age of easy 3D printing and other DIY innovations, that assumption may no longer apply.
In a workshop Friday at the Hackers on Planet Earth conference in New York, a German hacker and security consultant who goes by the name “Ray” demonstrated a looming problem for handcuff makers hoping to restrict the distribution of the keys that open their cuffs: With plastic copies he cheaply produced with a laser-cutter and a 3D printer, he was able to open handcuffs built by the German firm Bonowi and the English manufacturer Chubb, both of which attempt to control the distribution of their keys to keep them exclusively in the hands of authorized buyers such as law enforcement.
The demonstration highlights a unique problem for handcuff makers, who design their cuffs to be opened by standard keys possessed by every police officer in a department, so that a suspect can be locked up by one officer and released by another, says Ray. unlike other locks with unique keys, any copy of a standard key will open a certain manufacturer’s cuff. “Police need to know that every new handcuff they buy has a key that can be reproduced,” he says. “Until every handcuff has a different key, they can be copied.”
Unlike keys for more common handcuffs, which can be purchased (even in forms specifically designed to be concealable) from practically any survivalist or police surplus store, Bonowi’s and Chubb’s keys can’t be acquired from commercial vendors. Ray says he bought a Chubb key from eBay, where he says they intermittently appear, and obtained the rarer Bonowi key through a source he declined to name. Then he precisely measured them with calipers and created CAD models, which he used to reproduce the keys en masse, both in plexiglass with a friend’s standard laser cutter and in ABS plastic with a Repman 3D printer. Both types of tools can be found in hacker spaces around the U.S. and, in the case of 3D printers, thousands of consumers’ homes.
Over the weekend, a lockpick vendor at the HOPE conference was already selling dozens of the plexiglass Chubb keys for a mere $4 each. Ray says he plans to upload the CAD files for the Chubb key to the 3D-printing Web platform Thingiverse after the annual lockpicking conference LockCon later this week.
I reached out to both Chubb and Bonowi’s parent company Assa Abloy over the weekend, and will update this story when I hear back from them.
Ray also tried creating duplicate plexiglass key for high-security handcuffs from the German manufacturer Clejuso, but found that when the cuffs were fully secured the plexiglass wasn’t strong enough to overcome their internal springs. an attendee at the workshop helpfully suggested he try laser-cutting the stronger material Lexan instead.
Ray, who typically works as a computer security consultant but has also advised the German police on handcuff technology, says his goal isn’t to reduce handcuffs’ security so much as to exposing their vulnerabilities. His tools, he argues, are already available to criminals along with the rest of the public. “If someone is planning a prison or court escape, he can do it without our help,” says Ray. “We’re just making everyone aware, both the hackers and the police.”