The first time someone showed me security footage of a relay attack, I couldn’t believe how fast it happened. Two guys, 45 seconds, $70,000 Mercedes gone. No broken glass, no hotwiring, just two small electronic devices and some basic physics.
After 25 years in cybersecurity, I’ve seen a lot of theft methods. But relay attacks on keyless entry systems bother me because they’re so simple and so common. The equipment costs $100-300 online. No special skills needed. If you can use a walkie-talkie, you can steal a car.
Here’s what you need to know about protecting your vehicle from relay attacks, and why a simple Faraday pouch is the most effective solution.
Quick Answer
Car key relay attacks use two devices to amplify your key fob’s signal from inside your house to unlock your car outside. Thieves can steal keyless entry vehicles in under 60 seconds without touching your keys.
A Faraday pouch blocks your key fob’s radio signal completely, making relay attacks impossible. These signal-blocking pouches cost $15-30 and work immediately when sealed properly.
What Is a Relay Attack?
A relay attack exploits how keyless entry systems work. Your key fob constantly broadcasts a low-power radio signal. When you walk up to your car with the key in your pocket, the car detects this signal within a few feet and unlocks automatically. Push the start button and the engine starts. Convenient. The problem is that signal can be captured and extended. That’s exactly what relay attacks do.
How the Attack Works
Two thieves work together. One stands near your house with a relay device that captures your key fob’s signal from inside. This device amplifies the weak signal and transmits it to a second device. The second thief stands by your car with a receiver that rebroadcasts the signal right next to your car door.
Your car receives what looks like a legitimate signal from your key fob. The doors unlock. The thief gets in, presses the start button, and drives away. Your key never left your kitchen counter.
The Speed of the Attack
The whole process takes 30 seconds to two minutes. Most people wouldn’t notice anything suspicious if they happened to look outside. One person standing casually near your house, another walking up to a car like they own it.
How Fast This Actually Happens
I’ve watched dozens of security camera videos showing relay attacks. The speed is what gets me. This isn’t some complex heist requiring planning and inside knowledge. It’s two people with electronic devices executing a simple procedure.
Average time from approach to driving away: 45-90 seconds. Some skilled teams do it in under 30 seconds. By the time you notice your car is missing hours later, there’s nothing left but maybe some security footage of two people standing around.
No Warning Signs
No broken windows to alert neighbors. No alarm going off. No loud noises. Just two people who look like they’re supposed to be there, doing something that appears totally normal. The thieves are often gone before anyone realizes what happened. And because the car was unlocked and started with what the system thinks is the correct key, there’s no evidence of forced entry or tampering.
Which Vehicles Are Vulnerable
Any vehicle with keyless entry and push-button start is potentially vulnerable. This includes systems where you don’t need to remove the key from your pocket to unlock doors or start the engine. The scope of this vulnerability is significant, with security researchers finding that the overwhelming majority of keyless vehicles can be compromised using relay attack methods.
Luxury Vehicles Remain Top Targets
Luxury brands were early adopters of keyless systems and remain popular targets. BMW, Mercedes-Benz, Audi, Lexus, Range Rover, Tesla, Porsche, Jaguar. These vehicles have high resale value and established markets for stolen vehicles. Thieves often target specific models known to be easier to steal.
Security researchers have demonstrated successful relay attacks on dozens of luxury vehicles. The manufacturers release security updates, thieves adapt their equipment, and the cycle continues.
Mainstream Vehicles Face Equal Risk
Keyless entry spread quickly to mid-range and economy vehicles. Honda, Toyota, Ford, Chevrolet, Nissan, Hyundai, Kia. If your car was made after 2015 and has push-button start, assume it’s vulnerable unless you’ve verified otherwise. The equipment thieves use works across multiple brands and models. They don’t need different tools for each vehicle type. One set of relay devices handles most keyless entry systems.
Trucks and SUVs Are High-Value Targets
Pickup trucks with keyless entry face the same vulnerability as cars. Ford F-150, Chevrolet Silverado, Ram 1500. These are high-value targets with strong markets for stolen vehicles and parts. SUVs and crossovers with keyless systems are equally vulnerable. Toyota RAV4, Honda CR-V, Jeep Grand Cherokee. Family vehicles sitting in suburban driveways get stolen using relay attacks regularly.
Real-World Examples and Statistics
Police departments across North America and Europe have issued warnings about relay attacks. This isn’t theoretical. It’s happening in neighborhoods everywhere, and the data paints a concerning picture.
The Scale of the Problem
According to major UK insurers, between 60% and 70% of cars stolen in recent years were keyless models. That’s not a small portion of thefts. That’s the majority.
The trend has accelerated significantly, with vehicle theft incidents spiking by 48% in one recent year according to crime statistics from England and Wales.
The scope becomes even clearer when you look at specific tracking data. In the UK, keyless car theft reached an all-time high in July 2023, accounting for 98% of all stolen vehicles recovered by Tracker, a major vehicle recovery company, in that month. That’s nearly every stolen vehicle they dealt with.
Independent Security Testing
Security experts conducting independent testing have found vulnerabilities across the board. Germany’s largest automobile club tested 237 keyless cars and found 230 could be unlocked and started using relay attacks. That’s 97% of tested vehicles.
The equipment is cheap and widely available. Relay attack devices can be purchased online for as little as £80 (roughly $100), and they work across multiple vehicle brands. No special expertise required.
The Insurance Industry Response
Insurance claims for keyless entry vehicle thefts have increased significantly. Some insurers in high-theft areas now ask during policy applications whether you use signal-blocking protection for your keys.
A few offer premium discounts for using Faraday pouches. Insurance companies don’t ask questions or offer discounts without data backing up the risk. They’ve seen enough claims to know relay attacks are common enough to affect their business.
Soaring car theft rates have added hundreds of dollars per household in insurance costs in some high-theft states. The industry responds to increased theft by spreading costs across all policyholders in affected areas.
Law Enforcement Observations
Multiple police departments have recovered relay attack equipment from arrested suspects. The devices are real, available online, and being used actively. Security footage from residential areas shows the pattern: two people working together, one near the house, one by the vehicle.
Some neighborhoods see clusters of thefts over short periods. Multiple vehicles stolen within a few weeks, all with keyless entry, all taken overnight from driveways. Same method every time. The consistency of the attack pattern across different regions confirms this is a widespread, well-established theft technique.
Security Research Demonstrations
Researchers have demonstrated successful relay attacks on dozens of vehicle models. YouTube has videos showing how it works. Security conferences feature presentations on keyless entry vulnerabilities.
This information is public and accessible. The equipment used in demonstrations is the same equipment available for purchase online. Thieves don’t need to be security researchers or have advanced technical knowledge. The tools do the work.
How Relay Attack Equipment Works
Understanding the technology helps you understand why Faraday pouches work as protection. The equipment thieves use is surprisingly simple, which is exactly why relay attacks have become so common.
The Signal Capture Device
The first device captures the key fob’s signal. These units can detect signals through walls, windows, and doors. Effective range varies but typically works from 30-100 feet depending on the equipment quality and building construction. Some units look like briefcases or backpacks. Others are small enough to conceal easily.
The thief positions themselves near your house, often by your front door, garage, or wherever keys are typically stored. The device picks up your key fob’s broadcast and amplifies it.
The Signal Rebroadcast Device
The second device receives the amplified signal from the first unit and rebroadcasts it next to your vehicle. This makes your car think the key is right there. The system has no way to tell the difference between your actual key fob three feet away and a relay attack extending the signal from inside your house.
Communication between the two devices happens wirelessly. The thieves can be 300 feet apart or more depending on their equipment. One stays near your house capturing the signal, the other works on your vehicle.
Cost and Availability
Complete relay attack kits sell online for $100-300. They’re marketed as “car testers” or “range extenders” with legitimate-sounding descriptions. No special licenses required. Anyone can buy them. More sophisticated equipment costs more but offers better range and reliability. Professional theft rings use higher-end gear. Opportunistic thieves use cheaper equipment that still works on many vehicles.
The low cost and easy availability mean relay attacks will continue. As long as the equipment is cheaper than the cars they’re stealing, thieves have incentive to use this method.
Why Traditional Security Doesn’t Stop Relay Attacks
Most vehicle security measures don’t address relay attacks specifically because the attack doesn’t trigger traditional defenses. Understanding why your existing security fails helps explain why Faraday pouches work.
Car Alarms Are Ineffective
Your car alarm monitors for forced entry, impacts, and tampering. A relay attack doesn’t trigger any of these. The car thinks the legitimate key is present. Everything looks normal to the alarm system. The doors unlock silently, the engine starts normally, and the car drives away without the alarm ever activating.
Even sophisticated alarm systems with motion sensors and tilt detection won’t catch a relay attack during the initial theft. The alarm might activate later if thieves try to disable it, but by then they’re already driving your vehicle.
Immobilizers Get Bypassed
Engine immobilizers prevent starting without the correct key. They’re designed to stop hotwiring and forced ignition. But relay attacks don’t bypass the immobilizer. They make the car think the correct key is present. The immobilizer sees a valid key signal and allows the engine to start.
This is why relay attacks work so well. They don’t defeat security systems. They trick them into thinking everything is legitimate.
Cameras Document But Don’t Prevent
Security cameras document relay attacks but rarely prevent them. The theft happens fast enough that even if you’re watching your camera feed, you might not react in time.
By the time you see something suspicious and get outside, your car is gone. Cameras provide evidence for police reports and insurance claims. That’s valuable, but it doesn’t get your car back or prevent the theft in the first place.
How Faraday Pouches Stop Relay Attacks
A Faraday pouch creates a shield that blocks electromagnetic signals. When your key fob is sealed inside, its radio signal cannot escape. There’s nothing for relay devices to capture or amplify.
The Physics Behind Signal Blocking
Radio waves are electromagnetic energy traveling through space. Your key fob transmits on specific frequencies, typically 315 MHz or 433 MHz depending on your region. These signals pass through most materials easily. Fabric, plastic, leather, wood, drywall. Your key signal goes right through all of it.
Conductive metal behaves differently. When radio waves hit metal, electrons in the material react by moving and creating an opposing electromagnetic field.
This opposition cancels out or significantly weakens the original signal. A Faraday pouch uses fabric woven with or coated in conductive metal particles. Multiple layers of this material create a barrier that blocks radio frequencies. The key fob inside keeps broadcasting, but the signal stops at the pouch’s conductive layers.
Complete Signal Isolation
When properly sealed, a quality Faraday pouch provides complete signal blocking. Not reduced signal. Not weakened signal. Zero signal escaping. The key fob is electronically invisible to any device outside the pouch. Relay attack equipment can be right next to the pouch with maximum amplification and it will detect nothing.
No signal to capture means no signal to relay. The attack fails at the first step. This is different from just putting your keys in a drawer or behind concrete walls. Those materials reduce signal strength but don’t eliminate it. Relay devices are designed to amplify weak signals. A Faraday pouch prevents any signal from getting out in the first place.
Why Hardware Beats Software
Some key fobs have motion sensors that put them to sleep when stationary. This helps, but the fob still broadcasts for several minutes after you set it down. Thieves can act during that window. Software-based solutions depend on manufacturers implementing them correctly and thieves not finding workarounds.
A Faraday pouch is hardware-based protection using physics. There’s no software to hack or update. The electromagnetic shielding either works or it doesn’t. For more on the technical principles, how Faraday bags work covers the construction and physics in detail.
Choosing a Key Fob Faraday Pouch
Not all Faraday pouches work. I’ve tested dozens and found that about 30% of what’s sold online provides inadequate shielding or fails completely. Here’s what actually matters when picking one that will protect your vehicle.
Construction Materials Matter
Quality pouches have multiple layers of conductive material. Good products specify what metals they use: copper-nickel fabric, aluminum-coated material, or similar. They’ll tell you how many layers: typically two to four. Vague descriptions like “military-grade shielding” or “advanced protection” without specifics are warning signs. Companies that do proper shielding want to tell you exactly how they do it.
Seam Construction Is Critical
Seams are where cheap pouches fail. You can have perfect shielding material, but gaps at the seams let signals leak through.
Good pouches use overlapping seam construction or conductive tape along stitching. The closure mechanism matters equally. Roll-top closures that fold multiple times work well. Velcro closures need significant overlap. Standard zippers require a fold-over flap on top of the zipper to prevent signal leakage.
Size and Fit Considerations
Buy a pouch with room for your key fob plus a little extra space. Cramming the fob in tight can prevent proper sealing. A slightly oversized pouch is better than one that barely fits. Some pouches hold multiple key fobs if you have multiple vehicles. This works fine as long as you can seal the pouch properly with everything inside.
Look for Testing Data
Reputable manufacturers provide signal attenuation test results showing how many decibels of shielding they provide at specific frequencies. Look for testing across the frequency range key fobs use: 300-450 MHz typically. If the product listing doesn’t include any test data or just makes vague claims, that’s a red flag. Testing costs money and companies that skip it are cutting corners.
Price Range Guidelines
Quality key fob pouches cost $15-30. That’s the sweet spot where you get adequate shielding without paying for unnecessary features or brand markup. Pouches under $10 are usually inadequate. Over $50 and you’re likely paying for brand name or fancy materials that don’t improve performance. Price doesn’t guarantee quality, but there’s a reasonable range where quality products cluster.
How to Test Your Faraday Pouch
Testing is critical. Don’t assume your pouch works based on marketing claims. Verify it yourself. This takes five minutes and tells you exactly whether your protection is real.
Basic Functionality Test
Put your key fob in the pouch and seal it according to the manufacturer’s instructions. Stand next to your car and try to unlock the doors. Press the button on your car’s door handle if it has that feature. Try the trunk release. Nothing should work. Your car should act like the key fob doesn’t exist. If any function works, your pouch is either defective or you’re not sealing it correctly.
Distance Testing
Walk away from your car with the sealed pouch. Try unlocking from 10 feet away, 20 feet, 50 feet. The key shouldn’t work from any distance. A partially effective pouch might block the signal at distance but let enough through up close to unlock the car. You want complete blocking regardless of distance from the vehicle.
Remote Start Verification
If your vehicle has remote start, test that function with the key in the sealed pouch. Remote start often uses the same frequency as the unlock function.
It should not work when the key is properly shielded. Some vehicles have remote start through a smartphone app that doesn’t use the key fob. That will still work because it communicates through cellular networks, not the key fob signal.
Regular Testing Schedule
Test your pouch every few months. Materials degrade over time. The conductive coating can wear off, seams can separate, or the closure mechanism can weaken.
Regular testing ensures continued protection. If your pouch starts failing tests, replace it immediately. A pouch that worked when new but fails after six months of use isn’t protecting you anymore.
For detailed testing procedures including RF meter testing, how to test a Faraday bag covers advanced methods.
Using Your Faraday Pouch Correctly
Buying a pouch doesn’t help if you don’t use it consistently. Build habits that make protection automatic. The best security measure is worthless if it stays in a drawer.
Establish a Daily Routine
Keys go in the pouch when you get home. Every time. Not most of the time. Every single time.
Keep the pouch somewhere convenient: by your front door, in the kitchen, on your nightstand. Wherever you naturally set your keys down. If it’s inconvenient to use, you won’t use it consistently. That’s human nature.
Make it as easy as possible to do the right thing.
Proper Sealing Technique
Follow the manufacturer’s sealing instructions exactly. Roll-top pouches need multiple rolls. Velcro needs full contact across the entire closure. Fold-over flaps need to be folded completely.
A partially sealed pouch doesn’t work. The signal will leak through whatever gap exists. Take the extra two seconds to seal it properly.
Protecting Multiple Vehicles
If you have multiple cars with keyless entry, get separate pouches or one pouch large enough for all key fobs. All keys need protection, not just your newest or most expensive vehicle.
Thieves don’t care which car is newest. They care which car is easiest to steal and has the best resale value. Protect everything vulnerable.
Travel Considerations
Take your pouch with you when traveling. Hotel parking lots and rental properties are common theft locations.
Your routine gets disrupted when traveling, which is when it’s easiest to forget protection. If you’re staying somewhere temporarily, your keys still need to go in the pouch at night.
Thieves don’t take nights off because you’re on vacation.
Additional Protection Layers
Faraday pouches are the most effective single solution for relay attacks, but additional security measures provide defense in depth. Think of security like layers of an onion. Each layer makes theft harder.
Physical Steering Wheel Locks
Physical steering wheel locks are visible deterrents. Even if someone manages to get in and start your vehicle, they can’t steer it.
Most thieves move on to easier targets when they see one. These locks cost $50-150 for quality versions. They’re bulky and annoying to use daily. But if you’re in a high-theft area or have a vehicle that’s frequently targeted, the inconvenience is worth it.
Cheap steering wheel locks can be defeated with bolt cutters. Buy quality locks that resist cutting and can’t be easily removed.
Strategic Parking Choices
Park in well-lit areas when possible. Thieves prefer working in darkness where they’re less visible to neighbors and cameras.
Lighting doesn’t prevent relay attacks, but it makes thieves more hesitant to attempt them. Park close to your house if you’re in a driveway. The further your car is from where you keep your keys, the harder it is for relay devices to capture the signal.
This assumes your keys are in a Faraday pouch anyway, but proximity adds another layer. Garages provide the best protection if your keys are kept far from the garage walls.
A car in an attached garage with keys on the opposite side of the house makes relay attacks nearly impossible even without a Faraday pouch. But most people keep keys near the door to the garage, which doesn’t help.
Security Camera Systems
Cameras don’t prevent relay attacks but they document them. Good footage helps police investigations and insurance claims.
Position cameras to cover your driveway and street with clear views of faces and license plates. Motion-activated cameras with alerts to your phone might give you time to intervene during an attempted theft.
Though by the time you get the alert and react, thieves are often already gone. Visible cameras act as minor deterrents. Some thieves avoid properties with obvious surveillance. Others don’t care because they’re in and out so fast.
Insurance Considerations
Vehicle theft insurance coverage varies. Understanding your policy helps you know what’s protected and how relay attacks affect your rates.
Understanding Comprehensive Coverage
Comprehensive coverage pays for theft and vandalism. If you only have liability coverage, theft isn’t covered. Check your policy declarations to see what coverage you have.
Comprehensive coverage has a deductible, typically $500-1,000. You’ll pay that amount before insurance covers the rest.
If your vehicle is recovered damaged, comprehensive also covers repairs minus your deductible.
Premium Increases After Theft
Comprehensive claims can increase your insurance premiums even though you didn’t cause the loss. How much depends on your insurer, location, and claims history.
Some insurers offer claim forgiveness for first-time theft claims. Soaring car theft rates in some states have added hundreds of dollars per household in insurance costs.
The industry responds to increased theft by spreading costs across all policyholders in affected areas.
Anti-Theft Device Discounts
Some insurers offer premium discounts for anti-theft devices. Ask if using a Faraday pouch for your key fob qualifies.
Many insurers haven’t updated their discount programs to include this, but some have started asking about signal-blocking protection. Traditional anti-theft devices like LoJack, alarms, and steering wheel locks often qualify for discounts.
Installing them before a theft can reduce premiums and might offset the cost.
High-Risk Areas and Vehicles
Some locations and vehicle models face higher theft rates than others. Knowing your risk level helps you decide how seriously to take protection.
Geographic Risk Factors
Urban areas generally have higher vehicle theft rates than rural areas. But relay attacks happen in suburbs too. Thieves travel to where the high-value vehicles are, regardless of local crime rates.
Check local crime statistics for vehicle theft in your area. Police departments often publish this data. If your neighborhood has had recent keyless entry thefts, take that seriously.
Border areas and port cities see higher rates of vehicle theft because stolen cars are easier to move out of the country. Southern California, Texas border regions, Florida, and major port cities all experience elevated theft rates.
Most Frequently Stolen Models
Honda and Toyota models top theft lists consistently, though often for parts theft rather than relay attacks. Accord, Civic, Camry, Corolla. These vehicles have huge markets for stolen parts.
The Hyundai Elantra was the most stolen keyless car in early 2025, with over 11,000 thefts reported. That’s more than 2,000 ahead of the second-place vehicle. The Hyundai Sonata and Honda Accord also rank among the most frequently stolen.
Luxury Vehicle Targeting
Luxury vehicles get targeted for relay attacks specifically. BMW 3 and 5 series, Mercedes E and S class, Audi A4 and A6, Range Rover, Lexus SUVs.
High resale value and established export markets make these attractive to professional theft rings. Pickup trucks, especially full-size trucks like Ford F-150, Chevrolet Silverado, and Ram 1500, face high theft rates.
They’re valuable and have strong markets for both whole vehicles and parts.
The Cost-Benefit Analysis
Let’s be realistic about what you’re protecting and what protection costs. The math makes the decision pretty straightforward.
What a Stolen Vehicle Actually Costs You
Insurance deductible: $500-1,000 typically. You pay this upfront before getting any insurance payout. Time dealing with police reports, insurance claims, rental cars, and replacement vehicle shopping: easily 20-40 hours. Your time has value. Increased insurance premiums: varies widely but often $200-500 per year for several years after a comprehensive claim.
Hassle factor: dealing with a stolen vehicle is stressful and disruptive to your life. That has value even if it’s hard to quantify. Total cost even with insurance: easily $2,000-4,000 when you factor in everything beyond just the vehicle value.
What Protection Actually Costs
A quality Faraday pouch for your key fob: $20-30. One-time purchase that lasts years. Time to use it consistently: five seconds per day to put keys in and take them out. Maybe 30 hours over the life of your vehicle ownership.
The math is obvious. Spending $25 and building a simple habit prevents potentially thousands in costs and hassle.
Common Mistakes People Make
I’ve seen the same errors repeatedly when people try to protect against relay attacks. Avoiding these mistakes ensures your protection actually works.
Skipping the Testing Step
Buying a pouch and assuming it works without testing is the most common mistake. Test it when you first get it. If your car unlocks with the key sealed in the pouch, return it and buy a different one.
Inconsistent Usage
Using the pouch sometimes but not always provides inconsistent protection. Thieves don’t announce when they’re coming.
They scout neighborhoods and strike when opportunities arise. Your keys need to be in the pouch every time you’re home, not just when you remember.
Improper Sealing
Not following sealing instructions means the pouch doesn’t work even if the shielding material is adequate. Read the instructions. Follow them exactly. Verify through testing that your sealing method works.
Price as the Only Factor
The cheapest pouch on Amazon probably doesn’t work. But the most expensive one isn’t automatically better either. Look for verified testing data and clear construction details. Price should be one factor among several.
Forgetting Spare Keys
Protecting your primary key fob while leaving spare keys unprotected defeats the purpose. Relay attacks work on any key fob that’s broadcasting. Protect all keys, not just the one you use daily.
For more on car key relay attacks and comprehensive protection strategies, that guide covers additional details on the threat and countermeasures.
Frequently Asked Questions
Do relay attacks work on all keyless entry cars?
Most keyless entry vehicles are vulnerable to relay attacks. Research by Germany’s largest automobile club tested 237 keyless cars and found 230 could be unlocked and started using relay attacks.
That’s 97% of tested vehicles. Some newer models with motion sensor fobs or ultra-wideband technology have better protection, but the majority remain vulnerable.
How close do thieves need to be to my keys?
Thieves typically need to be within two to three meters (6-10 feet) of your key fob to capture the signal. However, relay devices can amplify weak signals, and some equipment can detect fobs from over 100 feet away through walls.
This is why keeping keys away from exterior walls helps but isn’t foolproof without signal blocking.
Will my car insurance cover relay attack theft?
Most comprehensive car insurance policies cover theft from relay attacks. However, insurers may require proof that you still have all available keys.
Since the car was unlocked and started with what appears to be the correct key signal, proving theft can sometimes be complicated. Having a police report and any security footage helps with claims.
Can I just turn off my key fob to prevent relay attacks?
Some newer key fobs allow you to manually disable the wireless signal, but not all models have this feature. Check your vehicle’s user manual.
If your fob has this option, it works as well as a Faraday pouch when disabled. But many people forget to turn it back on when needed, which can be frustrating. A Faraday pouch doesn’t require remembering to activate or deactivate anything.
How long do Faraday pouches last?
Quality Faraday pouches typically last 3-5 years with regular use. The conductive material can degrade over time from handling, moisture, and general wear.
Test your pouch every few months to verify it still blocks signals. If it starts failing tests, replace it immediately. For $20-30, replacing a pouch every few years is minimal cost for continued protection.
Do motion sensor key fobs prevent relay attacks?
Motion sensor fobs enter sleep mode when stationary, typically after 40 seconds of no movement. This prevents relay attacks while the fob is asleep.
However, the fob still broadcasts for those first 40 seconds after you set it down. Fast-acting thieves can potentially still capture the signal during that window. Motion sensors help but aren’t foolproof.
Can thieves jam my key fob signal to prevent me from locking my car?
Yes, signal jamming is a different attack method where thieves use a device to block the signal between your key and car. This prevents the car from locking when you press the button, though you may not realize it didn’t lock.
Always physically check your door handles to verify your car is actually locked, especially in parking lots.
What’s the difference between a relay attack and a CAN bus attack?
Relay attacks capture and extend your key fob’s signal to unlock and start your car. CAN bus attacks directly access your vehicle’s computer network through diagnostic ports or wiring to bypass security systems and program new keys.
Both are serious threats, but relay attacks are more common because they require less technical skill and work from outside the vehicle.
Are luxury cars more vulnerable to relay attacks?
Luxury cars were early adopters of keyless entry and became initial targets. However, keyless systems are now standard on most vehicles regardless of price.
The problem affects mainstream vehicles just as much. According to industry data, 82% of stolen light commercial vehicles were taken without keys, showing relay attacks impact all vehicle categories.
Can I make my own Faraday pouch?
Technically yes, but it’s not practical. You’d need multiple layers of conductive fabric with properly sealed seams and a reliable closure mechanism.
Most DIY attempts fail to block signals completely. For $20-30, buying a tested commercial pouch is more reliable than trying to build one yourself.
Protect Your Keys Starting Tonight
Relay attacks on keyless entry vehicles are real, common, and easy for thieves to execute. The equipment is cheap and available online. No special skills required. If you have keyless entry, you’re vulnerable.
A Faraday pouch for your key fob is the single most effective protection against relay attacks. It costs $20-30, works immediately, and requires minimal effort to use consistently. The physics is simple: no signal escaping means no signal to relay.
Test your pouch when you get it. Use it every time you’re home. Check it periodically to make sure it still works. That’s the entire protection strategy. Additional layers like steering wheel locks and security cameras provide defense in depth. But if you only do one thing to protect against relay attacks, get a quality Faraday pouch and use it consistently.
The goal isn’t paranoia. It’s appropriate protection against a documented threat. Your car is probably fine.But “probably” isn’t good enough when the solution costs $25 and takes five seconds per day.
Ready to protect your keys? Check out the best Faraday pouches for car keys to find tested options that actually block relay attacks.