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Keyless Car Relay Attacks: How They Work + Prevention

How do thieves steal cars with keyless entry (relay attack) and how can I reduce the risk?

A relay attack targets the convenience of keyless entry by extending the signal between your car and your key fob. Thieves typically work in pairs: one person stands near your front door or garage to “capture” the fob’s low-power signal, while another stands by the vehicle with a relay device. The relayed signal convinces the car the fob is nearby, allowing doors to unlock and, on many models, enabling the engine to start. Once running, the vehicle can often be driven away and kept running long enough to disappear, be reprogrammed, or be stripped.

You can reduce the risk by shrinking the signal footprint and adding layered deterrents:

Store fobs in a signal-blocking pouch (Faraday bag) at home and when traveling; test it by standing next to the car—if it still unlocks, the pouch isn’t working.
Keep keys away from entry points like doors, windows, and the garage wall closest to the driveway.
Disable passive entry features if your vehicle allows it, or use “sleep mode” on fobs that support it.
Add physical deterrents such as a steering wheel lock; thieves prefer fast, quiet targets.
Use a tracking solution and make sure your security settings, app access, and PINs (if available) are up to date.
Park strategically in well-lit areas, nose-in, and consider a driveway security post or garage parking when possible.

For a practical, step-by-step checklist (including what to buy and what to change in your routine), see the full guide here: keyless car security checklist to help stop break-ins and theft.

For Keyless Car Relay Attacks: How They Work + Prevention, the best answer depends on fit, material, care instructions, and how the product will be used day to day.

FAQ

Does a Faraday pouch really block key fob signals?

A good-quality Faraday pouch can block the frequencies most fobs use, but quality varies. Always test it against your own car and replace it if it stops working or the lining wears out.