The RollJam is a $30 Invention which Intercepts your auto Key Fob

But this time, Kamkar’s device will re-transmit the first code and unlock the vehicle, so the victim thinks everything’s alright.

Kamkar has recently unveiled a device that costs about $30 to make and has the ability to unlock and open auto doors or garage doors that rely on keyless entry.

The convenience that keyless entry systems provide cannot be denied, as door cars can be unlocked and garage doors opened with just a simple press of a button. In theory, if an attacker intercepts a code during transmission, a rolling code system makes the intercepted code useless for repeat entry attempts.

For most consumers, the DEF CON hacker convention is a place to hear about how vulnerable every single electronic device in your home is, but it serves a very useful objective: it educates developers on how to code smarter. Both key and vehicle use sophisticated mathematics to generate a new code in tight synchronisation each time an unlock attempt is made – and only a key that generates a code the auto is expecting will unlock the door. This code is also intercepted and blocked, but then RollJam then sends the first signal to the vehicle to unlock it – much to the owner’s relief.

The RollJam stops the signal from the first button press and records the code sent to the garage. How it works is that when a vehicle own presses the button to open the door, a simple radio interference on the same frequency will stop the signal from reaching the garage or auto.

The RollJam is designed to be used in the near vicinity of a targeted vehicle or home, but the device is so small it can be easily hidden while it autonomously does its thing. The person will realize their auto hasn’t been unlocked, and so will use their key fob a second time. “This has been sort of a theoretical attack for many, many years”. He plans to reveal more information about the hack Friday during a talk at the hacking conference Defcon in Las Vegas.

Kamkar’s hack affects may auto brands, including those from Nissan, Cadillac, Ford, Toyota, Lotus, Volkswagen, and Chrysler and security systems from Cobra and Viper.

Does this mean you should go out and buy a new vehicle?

“The problem is no one has really demonstrated it, which is amusing because the solution to this problem has been known about for more than 20 years and has been written about many times, but again no one has demonstrated it”, Kamkar said.

“So a lot of manufacturers haven’t cared to solve the problem because it didn’t seem like a big enough problem”. In fact he doing the opposite.

His latest nifty gadget built out of $32 worth of electronics.