![hackrf one unlock rolling code hackrf one unlock rolling code](https://raw.githubusercontent.com/s34s0n/jam-replay-rf/master/image/c2.jpg)
Keyless Entry SystemsĪ remote keyless entry system simply refers to any electronic lock that functions without the use of a mechanical key. Then uses a Raspberry Pi running RPiTX to generate a jamming signal, and the HackRF to capture and replay the car keyfob signal. In this demonstrating I had used the HackRF to initially find the frequency that the key fob of Maruti Suzuki WagonR operates at and to analyze the signal and determine some of its properties. Note that if the user unlocks the car using the mechanical key after the first try, the second code capture is not required, and the first code can be used to unlock the vehicle. The process can be repeated frequently by placing the device in the proximity of the car. This results in the attacker possessing the next valid rolling code, granting them access to the vehicle. When the user presses the key fob again, the device captures the second code and transmits the first code, so that the user’s required action is performed. The device simultaneously intercepts the rolling code by using a tighter receive band, and stores it for later use.
![hackrf one unlock rolling code hackrf one unlock rolling code](https://hackster.imgix.net/uploads/attachments/972829/1_4vL7HFNObJD9i5QQf6h6bQ.png)
This is possible as Remote Keyless Entries are often intended with a receive band that is wider than the bandwidth of the key fob signal.
Hackrf one unlock rolling code validation code#
The attacker appropriates a device with simultaneous transmit and receive capabilities to produce a jamming signal, to restrict the car from receiving the validation code from the key fob. Just to be clear, I worked on this project because I was interested in learning the basics of radio and how data is modulated.