Why Police Recommend Wrapping Your Car Keys in Aluminum Foil

In a world where technology evolves faster than most people can keep up with, even something as simple as your car keys can become a potential security risk. That’s why police departments in several regions have issued an unexpected but important warning:

Keep your car keys wrapped in aluminum foil.

At first glance, it sounds like a strange hack from an internet forum. But there’s a real, serious reason behind the advice—and it has everything to do with how modern cars are stolen today.

The Rise of “Relay Attacks”

Most newer cars use keyless entry systems. These keys constantly emit a small radio frequency signal. When you approach your vehicle, it detects the signal and unlocks automatically—convenient, right?

Thieves think so too.

Criminals now use a technique called a relay attack. Here’s how it works:

1. A thief stands near your house (often at night), holding a relay device.
2. Another thief stands near your car with a second device.
3. The first device captures the signal from your key fob inside your home.
4. It then amplifies and transmits that signal to the second device.
5. Your car thinks the key is nearby—and unlocks.
6. The thieves can then start the vehicle and drive off, no damage required.

All of this can happen silently, in under 30 seconds.

How Aluminum Foil Helps

Wrapping your key fob in aluminum foil creates a simple, effective barrier known as a Faraday shield.

A Faraday shield blocks the radio signals emitted by your key.
If no signal escapes, thieves have nothing to intercept.

Aluminum foil works because:

• It is conductive.
• It disrupts electromagnetic fields.
• It prevents scanners and relay devices from reading your key fob.

It’s not fancy, but it does the job.

Why Not Just Turn the Key Off?

Some key fobs can be switched off—but many can’t.

Others have “sleep modes,” but you must remember to enable them every time. Most car owners don’t know these features exist or forget to use them.

Foil, on the other hand, is simple, cheap, and requires zero tech knowledge.

More Secure Alternatives

If you want something more durable than foil, consider:

✔️ Faraday pouches or key signal-blocker cases

• Lined with special conductive material
• Designed specifically to stop wireless attacks
• Affordable and widely available

✔️ Store keys away from doors and windows

Thieves often scan near the front door, where people typically hang keys.

✔️ Disable keyless entry (if your car allows it)

Some manufacturers provide instructions in the owner’s manual.

Why Police Push This Message Now

Car theft using “relay” technology has skyrocketed over the past few years. Some cities report up to a 60% increase in keyless car thefts.

The most targeted vehicles?

• SUVs
• Modern push-start cars
• Luxury brands
• Any vehicle with passive entry

Because it leaves no signs of forced entry, insurance claims become complicated—and sometimes denied.

The Bottom Line

Criminals have found a way to hack cars without ever touching your keys.
Police know the risks, so they’re encouraging people to use simple, practical protection.

Aluminum foil might look odd…
But if a 30-cent solution can prevent a $30,000 theft?

It’s absolutely worth it.