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Car thieves suspected of abusing smart keys in Osaka Pref.

In this video grab from footage provided by a resident, a man assumed to have used a "relay attack" to unlock a car, are seen in September 2018, in Higashiosaka, Osaka Prefecture.

OSAKA -- A new car theft method abusing the smart key system for unlocking and starting a car from close by was apparently used in multiple locations in the western Japan prefecture of Osaka, according to investigators.

A smart key works when the signals it emits match those from the vehicle. This feature is taken advantage of in a car-jacking technique called a "relay attack," which tricks the smart key into determining that the car is only about a meter away by amplifying the weak signal from the vehicle using special devices.

The relay attack allows thieves to steal a car parked outside an owner's home quickly without noise by activating the key fob inside the house.

The method is thought to originate abroad, and police are warning people who use the keyless ignition system to take countermeasures such as placing the key fob in a special signal-blocking container as well as locking the steering wheel and the tires.

An attempted car theft using the technique was captured with a security camera at a resident's home in the city of Higashiosaka, Osaka Prefecture in mid-September last year, when multiple men tried to steal a Lexus, a luxury brand of Toyota Motor Corp.

In the footage, a masked man wearing a backpack in front of him is seen approaching the entrance of the house around 3 a.m. The man extended an object that resembles an electric cord, and shortly after, the hazard lights on the car parked nearby flickered, indicating that the doors were unlocked in only about five seconds.

The man is believed to be in charge of relaying the cars' signals to the fob, and another person considered to be his accomplice was also spotted near the car. The two men fled after noticing a passerby and failed to steal the car, but Osaka Prefectural Police are investigating the case as an attempted theft. The 37-year-old owner of the car was surprised that it "could be unlocked so easily" when he saw the video.

A spate of car thefts has recently taken place in Osaka Prefecture, which are all suspected to be relay attack incidents -- one in the city of Moriguchi in May last year and two more in the cities of Ibaraki and Sakai this January. A person close to the investigation said that police suspect the stolen cars were sold after the attack by making a new smart key.

According to a representative of an automotive supply store M'z Speed in Higashiosaka, who is knowledgeable about car theft countermeasures, relay attacks have spread in European and other countries. An automotive industry association in Germany in 2016 released a video describing the technique and asked owners to take proper precautions, followed by British police who publicized similar footage the next year.

(Japanese original by Takuya Murata and Haruka Ito, Osaka City News Department)

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