Savvy thieves only need a key's number to gain access

"Returning home, we first noticed something was amiss when we saw the slippers' toes were pointing in the wrong direction. And the TV remote control wasn't in its usual place. The windows had not been left open and there were no scratches on the door lock to indicate forced entry. But things were missing. No one had lost their key. How could this have happened?" 

Incidents of this nature, reports Shukan Post (June 4), have been increasing of late. 

On May 10, a former medical student, 37, was arrested for breaking into a condominium shared by several university co-eds. His interrogators were to learn that between September 2014 and last January, the man had broken into 164 residences in order to pilfer articles of underwear. 

Explaining his motives, he had told police, "I broke into homes because I wanted a view of worlds that typically can't be seen." 

More surprising than his motives, however, was his method. During his years as a student, he became aware that female students frequently left their handbags unguarded atop their desks. He would steal a glance at the numbers imprinted on the keys, or photograph them, which was sufficient to produce a passkey. Then after asking around to determine the key owners' addresses, he would await an opportunity to break in. 

But, the magazine asks, is it possible to produce a passkey simply from knowing a key's number? 

"The original keys that manufacturers ship with the locks are imprinted with a 10-digit alphanumeric code," a spokesperson for the Japan Lock Security Federation in Kanda explains. "So the system has been set up so that in nearly all cases, spare keys can be procured by sales agents nationwide." 

Of course, some additional steps are required to complete this process, which, to avoid antagonizing the police, Shukan Post wisely omits from its explanation. 

Other cases have occurred. In November 2020, Kobe police arrested a man in his 30s for repeated break-ins, during which he stole over 4 million yen in cash and other items. His modus operandi was the same in that he was able to catch a glimpse of the numbers on his victims' keys. 

Between February 2017 and August 2019, a staff member of the Saitama prefectural police forensics laboratory, a man in his 30s, broke into the dormitory rooms of two female staff members on multiple occasions. When arrested, police determined he had used the same method to break in. 

According to data from the National Police Agency, 3,309 incidents of break-ins occurred during 2016, in which entry was gained by use of a passkey. In addition, stalkers have utilized passkeys for their own nefarious ends. 

Even the so-called magnetic "dimple keys," which are supposed to be able to thwart copying by potential thieves, appear to be vulnerable if their number can be obtained. 

"These keys gained wider use about 20 years ago, when the number of burglaries due to lock picking became widespread," said Japan Lock Security's representative. "But with more sales of locks being made via the internet or mail orders, unauthorized people outside of official sales channels became involved, and even dimple keys could be duplicated once their number fell into the hands of the wrong people. The importance of maintaining security of the numbers on keys cannot be overlooked."  

People at restaurants, gyms and at work often leave their keys unattended long enough to give criminals the opportunity to obtain the number. 

What to do then? For added security, Japan Lock Security offered this simple solution: "The numbers on duplicate keys are only 3 or 4 digits, so a thief can't obtain enough data needed to make a copy. It's safer for you to store your  original in a secure place and use a duplicate when you go out."

© Japan Today