Modern key fobs offer unparalleled convenience, allowing you to unlock and start your car without even taking your keys out of your pocket. But this convenience comes with a security risk: keyless car theft. These fobs use radio-frequency identification (RFID) and short-range radio transmitters to communicate with your vehicle. Understanding how they work is the first step in protecting yourself.
Key fobs are designed to transmit a coded signal to your car when activated, usually by pressing a button or when in close proximity to the vehicle. This signal is received by a unit in your car, which then unlocks the doors or starts the engine. To prevent constant signal broadcasting and save battery, fobs only transmit when prompted. When your car senses the fob nearby, it sends out a low-frequency (LF) signal. If the fob is close enough, it’s activated and responds by transmitting its unique ID back to the car via radio frequency (RF).
To test signal blocking, a simple experiment can be performed. Placing a key fob in a steel coffee can effectively blocks the signal. In one test, a fob inside a steel can failed to unlock a 2020 Honda, demonstrating signal blocking in action. Similarly, wrapping a fob in aluminum foil, even loosely, also prevents the signal from reaching the car. Unwrapping the foil immediately restores the fob’s functionality.
Key fob placed inside a metal container to block its signal, demonstrating a method to prevent keyless car theft.
This is where key fob signal blocking boxes come in. Storing your key fob in a metal box, similar to an old biscuit tin or a specially designed signal blocking box, can effectively block the communication between your key and car. This is because metal acts as a Faraday cage, preventing radio waves from passing through. By blocking these signals, you prevent thieves from using signal amplification or relay attacks to clone your fob and steal your car. For on-the-go protection, a Faraday pouch serves the same purpose. Investing in a key fob signal blocking box or pouch is a simple yet effective measure to enhance your car’s security in the age of keyless entry.
