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How to Protect Your Car Key Fob from Relay Attacks

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25.04.2025

Car theft has entered the digital age — and unfortunately, so have the thieves. As car manufacturers move toward keyless technology, a new type of threat has emerged: the relay attack. Unlike traditional break-ins, this high-tech method allows criminals to steal a vehicle without touching the keys — or even breaking a window.

Imagine this: your car is parked safely outside your house. Your key fob is inside, hanging on a hook by the front door. You're fast asleep. But outside, two individuals with small electronic devices are working together. One stands near your front door, scanning for a signal from your key fob. The other waits by your car. Within seconds, your key’s signal is captured, extended, and transmitted to your car. It unlocks, starts, and drives away — and you might not notice until morning.

This is not science fiction. It's called a relay attack, and it's one of the fastest-growing vehicle theft methods worldwide.

Why Relay Attacks Are So Effective

The key to this technique is exploiting the constant communication between your car and its fob. Most keyless entry systems are designed for convenience — you don’t even need to press a button. The car automatically detects the presence of the key fob and unlocks when you approach.

This convenience is exactly what makes it vulnerable. Relay devices — which are cheap, portable, and easy to use — can mimic the signal and trick the car into thinking the key is nearby, even when it’s inside your home.

Security experts have raised the alarm about this method for years, but many drivers still don’t realize how easily their vehicles can be accessed. In the UK alone, keyless car theft now accounts for more than 90% of vehicle thefts involving high-end models, according to the AA. And with the rise of online tutorials and black-market tools, the problem is growing globally.

So, What Can You Do to Stay Safe?

Fortunately, protecting your vehicle doesn’t require advanced tech or a huge investment — just awareness and a few smart habits.

One of the most effective ways to block relay attacks is also the simplest: store your keys in a signal-blocking container. Often called a Faraday pouch or Faraday box, this lined case prevents radio signals from escaping. When your keys are stored inside, they can’t be scanned or cloned, no matter how close a thief gets to your home.

Placement also matters. Many drivers leave their keys near the front door or on an entryway table — spots that are easy to access from outside. Moving your keys to the center of your home, an upper floor, or even a metal box can reduce signal exposure dramatically.

Some newer key fobs allow you to manually disable the signal when it’s not in use. This feature is often hidden in the manual and rarely mentioned by dealers. Taking a moment to learn whether your key supports this — and how to activate it — can make a big difference.

It’s also worth checking whether your vehicle’s software is up to date. Many automakers periodically release firmware updates that strengthen encryption or reduce signal range. In some cases, updates can even detect and block suspicious unlock attempts.

And while it may seem old-fashioned, physical security still works. Devices like steering wheel locks or gear shift immobilisers can be powerful visual deterrents. Even if a thief manages to unlock your vehicle, the sight of a bulky lock inside may be enough to send them looking for an easier target.

If you're looking for practical solutions beyond GPS, check out our blog: Do Car Keys Have GPS? What You Need to Know About Key Tracking.

In summary, here are a few key takeaways to keep your keys and vehicle safer:

Store your fob in a signal-blocking pouch or metal container

Keep keys away from entry points like doors or windows

Disable keyless signals if your fob supports it

Update your car’s firmware regularly

Use visible anti-theft devices as a deterrent

Looking Ahead: Smarter Cars, Smarter Drivers

Relay attacks are part of a larger trend — one where modern technology makes life more convenient, but also creates new risks. Just like we’ve learned to secure our phones and passwords, we now need to think about how we secure our vehicles.

As carmakers explore more secure solutions — like Ultra Wideband (UWB) tech and biometric verification — drivers still need to take responsibility for their vehicle’s safety. The tools are already out there, and many of them cost less than a meal out. It’s not just about avoiding theft; it’s about peace of mind.

So next time you get home, before tossing your keys on the hallway table, take a second to think: are they really safe there?

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Can I order a replacement car key online with delivery?

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Electronics are checked before dispatch. 4. Delivery in 3–4 days Typical UK delivery with tracking and updates. 5. Local programming Arrange a nearby automotive locksmith to pair the key. Most jobs take 15–30 minutes. What affects cost Key type — proximity and smart keys cost more than basic transponders. Electronics and frequency — differ by brand and year. Cutting method — photo or code; standard or laser blade. Programming complexity — varies by model. Extras — spare shells, emergency blades, or upgraded housings. Pro tip: Order two keys now — you’ll save money on future locksmith visits and prevent lockouts. Programming: DIY vs local locksmith Modern immobilisers are secure by design. Mr-Key does not supply pairing or programming kits. A professional locksmith uses diagnostic tools to safely program your new key and verify vehicle ownership. It’s faster, safer, and ensures full functionality. Shipping, warranty & returns Delivery: 3–4 days across the UK. Warranty: 12-month full coverage on keys and electronics. Returns: Contact support before programming — unused items are easier to exchange. Dealer vs local locksmith vs online Option Speed Convenience Programming Best for Main dealer Medium–slow Appointment required Dealer tools Brand-new cars, under warranty Local locksmith Fast Mobile visit Done on site Emergencies, quick help Online (Mr-Key) 3–4 days Order from home Done by locksmith Planned replacements, spares Most UK drivers choose online ordering + local locksmith pairing — the fastest, most cost-efficient combination. Troubleshooting after delivery Key turns but car won’t start Blade fits, but immobiliser isn’t paired yet. Book a locksmith. Remote buttons not working Replace the battery and re-pair during programming. Proximity key not detected Use the emergency start position (usually near the steering column) and ask your locksmith to register it. Blade feels rough Use light graphite lubricant or send a photo for recheck. How to avoid another lockout Order a second key and keep it at home. Replace weak remote batteries yearly. Label your spare with the vehicle reg. For keyless cars, store keys away from doors and use a signal-blocking pouch. FAQ Can I order a replacement car key online and get it delivered? Yes. Send your key photo or code, receive delivery in 3–4 days, and have it programmed locally. Do I need proof of ownership? Your locksmith may ask for it. For UK vehicle documentation, see GOV.UK – V5C log book . What’s the difference between key types? Transponder keys start the car; remote fobs add buttons; proximity keys enable keyless entry/start. Can you cut my key from a photo? Yes. Clear, well-lit images allow accurate decoding and cutting. Can I program the key myself? No. Only an automotive locksmith can safely pair it. How long does delivery take? Usually 3–4 days within the UK. Do you cover my vehicle? Almost all brands plus caravans, ATVs, lockers, and more. 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Can a Locksmith Cut a Key from a Photo or Code?
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Can a Locksmith Cut a Key from a Photo or Code?

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When a photo is “good enough” If you’re ordering car keys cut by photo or utility keys by photo , expect guidelines like: Flat, well-lit, high-resolution image; key blade perfectly side-on. Ruler/coin in frame for scale; entire blade visible, shoulder to tip. For double-sided/laser keys, shots of both sides. Keyway/profile identification (brand/series). Automotive: cutting from photo or code—plus programming Cutting the blade is only step one for modern cars. Since the late 1990s, most vehicles have immobilisers ; the key’s transponder chip must be recognised or the engine won’t start. In practice: Get the correct blank and cut it (photo or code). Program the transponder/remote (OBD or on-board procedures), or pair a proximity fob. Test mechanical operation and ignition start. Main points UK readers should know: Immobiliser/transponder tech became standard in the mid-1990s; without a programmed chip, a correctly cut key usually won’t start the car. A key code specific to your vehicle lets a locksmith/dealer cut precisely without an original; some guides explain where owners can find it. Utility keys we commonly see cut by code If you have the key code , these are routinely cut accurately online: Retro automobile keys (classic patterns; often stamped codes). Caravan & motorhome key s (e.g., ZADI, FAP/FAWO—codes on barrels). E-bike battery keys (e.g., ABUS/AXA series). Furniture, mailboxes keys (office furniture, cam locks). ATV/quad ignition and compartment keys. Roof racks (e.g., Thule N*** series). Towbars (e.g., Westfalia/Brink code series). For these categories, supplying the printed code (from the lock face, key head, manual, or tag) usually yields the fastest, most reliable result compared to photos. Accuracy expectations & limitations What typically works well Flat cylinder keys with standard depth systems (common utility keys). Many car blades (including laser/sidewinder) if the image is clean and scaled. Keys where the lock/brand series is known and the bitting can be derived . What may be restricted or not feasible from a photo Patented/restricted keyways (require authorised proof and controlled blanks). Highly worn, bent, or obscured keys in photos. Complex security keys that need factory or authorised dealer processes. Car keys where programming tokens, PINs, or security codes are required. For security and consumer protection in the UK, look for MLA-approved locksmiths and insist on identity/ownership checks for sensitive work. Real-world risk: why photos can be enough Academic work and well-reported incidents show that key geometry can be decoded from images at surprising distances. Media have covered expensive lock replacements after keys appeared on camera, underlining the practical risk of sharing key images online. Keep your keys out of frame. What an online order typically requires For car keys (photo or code): Vehicle make/model/year, blade type, and VIN if needed for code retrieval. Clear photos (both sides). Programming method: mobile visit, on-site, or mail-in ECU/fob (varies by model). Expect additional steps for remote locking and proximity systems. For utility keys (cut by code): The code from the lock face or original key (e.g., N123 , Z **). Brand or system (Thule, Zadi, Westfalia, etc.). Quantity and turnaround needs (next-day options often available). Speed and success rates By code : fastest and most consistent for; minimal adjustment needed. By photo : slightly more validation and back-and-forth; still accurate when images meet spec. Why choose an online key cutting service like MR-KEY Unlike traditional emergency locksmiths who mainly handle urgent lockouts, MR-KEY specialises in precision key cutting from photos or codes — ideal when you’re not locked out but need an exact replacement or spare . Through our online platform, you can: Order from anywhere in the UK — simply upload a clear photo or enter your key code. Get fast, expert cutting using professional decoding software and calibrated machines. Receive your key by post , ready to use or, for vehicles, to be programmed locally. With MR-KEY, you save the cost and time of a mobile visit while still getting locksmith-level precision. Each key is verified before dispatch to ensure perfect fitting and reliable operation. FAQs Can a locksmith cut a car key from a photo? Often yes, the blade can be cut from a high-quality photo , but modern cars also need transponder/immobiliser programming before the engine will start. Is cutting by code more accurate than using a photo? For most utility keys , yes . A verified key code maps to exact cut depths, making the process highly repeatable and quick. Can someone copy my key from a social media photo? It’s technically possible; public cases and research have shown keys can be decoded from images . Avoid posting close-ups of keys online. What’s the difference between “key cutting,” “key replacement,” and an “emergency locksmith”? Key cutting : the physical milling of a blade (by code/copy/photo). Key replacement : end-to-end service supplying a working key/fob (cutting + programming if needed). Emergency locksmith : rapid response for lockouts or urgent access/security issues. Order your new key today at mr-key.com — fast, accurate, and cut by professionals from your photo or code.

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