Starting today, it’s a good idea to wrap your car key in aluminum foil—not because it’s trendy or part of a conspiracy theory, but because it’s actually a practical, low-tech way to protect your vehicle from being stolen in a high-tech world. Most modern car keys use wireless technology to constantly transmit signals to your vehicle, which makes it easy for you to unlock the doors and start the engine without physically inserting the key.
While this technology is certainly convenient, it also comes with a serious downside—those signals can be intercepted by thieves using devices that are inexpensive and easy to find online. Cybersecurity experts have been raising the alarm about this issue for years. If criminals can capture the signal your key emits, they can replicate the code and trick your car into thinking the key is nearby, unlocking and even starting your car without ever touching the original key. In other words, your car can be stolen without the thief even breaking a window or picking a lock.
Fortunately, the fix is surprisingly simple: wrapping your key in aluminum foil. It might sound a little old-school, but aluminum foil acts as a barrier that blocks electromagnetic signals. When you wrap your key in foil, you create a mini Faraday cage that prevents the signal from escaping and being picked up by hackers. Cybersecurity professionals admit that while it’s not the perfect solution, it’s a cheap and effective way to protect your car from a growing threat. For those who want a more permanent and durable fix, you can buy a Faraday bag online for just a few dollars.
These bags are specifically designed to block wireless signals and serve the same function as foil, just with a bit more style and practicality. Moshe Shlisel, CEO of GuardKnox Cyber Technologies and a former developer for Israel’s Air Force missile defense systems, explained the concept in simple terms during an interview with BBC Mundo. He described it like a radio that plays a unique song—a song that your car recognizes. When it hears that song, it unlocks and starts. If someone else records or replicates that song, they can use it to access your vehicle. Aluminum foil, or a Faraday bag, stops that song from being broadcast in the first place. Some people might find it odd or even outdated that in this day and age we’re still relying on aluminum foil to protect high-end tech like smart car keys, but experts insist it’s a real and growing problem.
While exact numbers are hard to pin down, there’s plenty of anecdotal evidence and police reports showing an increase in keyless car thefts. Shlisel points out that the tools needed to pull off these signal hijacks are now widely available. You don’t have to be a professional hacker to do it—anyone with access to the internet and a bit of curiosity can order the devices and watch YouTube tutorials that walk them through the process step by step. That accessibility makes this form of theft more common than many drivers realize. Automakers are aware of the problem and are actively working on ways to strengthen the communication between the key and the car so it can’t be easily copied or faked. Until those advancements become standard in all vehicles, though, drivers are encouraged to take basic precautions to protect themselves. It may seem inconvenient to wrap your key in foil or carry it in a Faraday pouch, but those few extra seconds of effort could mean the difference between keeping your car safe and becoming a victim of tech-savvy theft. In a world where convenience often comes at the cost of security, it’s important to be proactive. Something as simple and old-fashioned as aluminum foil could be your best defense against a modern-day crime.
