Repeater hack for keyless entry

Thanks for this Bob.

I'm missing old school car keys for three reasons now:

1. Crazy expense of replacement fob
2. Danger of leaving car running
3. Security

 

those faraday bags 'hgs' suggested look pretty cool.

 

Does anyone have a link to the devices on "eBay, Amazon and Craigslist."? I keep seeing lots of scare stories on this topic, but no evidence that any reporter has actually verified them.

 

One big selling point of the no-touch fob was convenience. Kinda defeats the purpose if you've gotta rigorously store the thing in a transmission blocking container.

 

Meh...
Give me an RFID embedded key, any day.
I'd also try an Altoids tin before attempting to build a Faraday cage or the Alcoa maneuver.
That way your keyfob always smells minty fresh!

The good thing about this 'hack' is that right now it's like a unicorn.
Everybody knows what they are, and lots of stuff about them, but nobody has ever really seen one, let alone touched a for-real example.

It also seems to be a just a high tech rock---intended only to get into the car.
Since I choose to live where I can keep my car unlocked pretty much all the time, it's not the top turd on my pile.
In fact....the only time I ever had a vehicle broken into, it was actually unlocked at the time....AND in a lot with an armed guard. I immediately suspected an inside job, but the guard's car was also broken into - and you cannot fake that level of anger. I was actually pretty happy about that - since he was obviously not very good at his job.

We're required to keep our work cars locked at all times, and when they're parked at night they're supposed to be well away from fences, since some of our vehicles have some fairly spendy stuff inside......and some of the cities I work in are NOT crime-free.
Still.....I've never heard of a vehicle that was hacked into outside unconfirmed reports here in PC.

If it starts happening?
It's Big Bell's problem. My personal car has proper locks.
Currently not.....

 

i think you're okay if you live outside cali and florida.

 

"Easier, just keep the key fob in a small, metal cup when home or in the office. You can test it by waking to the car with the key fob in the cup. If the car does not open, the cup works."

I tried an Altoids tin, but it did not work. I bought two Faraday Bags from Amazon, and they work great. See my thread with pictures, articles, and video of a break-in.

Faraday Bag for Smart Key (SKS) Break-in Protection | PriusChat

 

My cousins were clearly way ahead of their time: they'd mastered keyless entry and keyless ignition way before Toyota or Ford or anyone.

In the 80s, we went to visit my uncle in a fairly rough town about 40 or 50 miles from where I lived (the town Rick Astley is from, in fact). While we were there, my uncle wanted to go out and get some cigarettes, but he'd lost his car keys.

"Don't worry, Dad," said his helpful elder son (who was about 11 at the time). "I'll sort it out."

It took him 30 seconds with a coat hanger to unlock the door, and another minute to hotwire it.

Keyless entry. Keyless ignition. And all in the mid-80s.

Oooh, I felt some familial pride that day, I can tell you.

 

As I understand the system, the key does the calling, not the car. The amplifier would need to work with the key, which actually makes more sense. It would take two devices- one near the key and the other near the car.

 

Some PC members have the idea that just because it's not easy to find these key fob boosters online for sale on, Amazon, EBay, etc, that they do not exist.

Though I don't know how to make one, it makes sense that a person that knows how to build circuits and small transmitters could make a transmitter that could pick up a very weak key fob signal and boost the power so the car thinks the key fob is within a few feet. Or, if it's the car transmitter that is boosted, same idea. Probably not hard to make for the "circuit board building, electrically inclined"' type.

 

I'm quite prepared to believe they exist - as soon as I see one, along with a technical description of exactly how it works.

 

Actually?
I hope that they DO exist!
The last time my car was broken into (while traveling) the moron broke out a window only to discover that (1) the car was unlocked and (2) I don't leave valuables in my car.
If that person would have used an RF booster?
Then I wouldn't have had to replace my glass.

Besides.....the fix for this "problem" would entail dealing with the only real problem that I have with the car.....the weirdly named "smart-key" system.



EDIT: OK.....I'll admit it. There ARE a few other small problems!

 

Basic electrical physics demands that the pickup be placed very close to the weak signal. A certain floor level of electrical noise exists in all our devices, from the random thermal motion of the electrons in the matter they are built from. This noise overwhelms very weak signals and cannot be removed, amplifier gain boosts both equally. Therefore the receiving antenna must be placed close enough to the transmitter for the received signal to exceed the electron noise.

The thieves do not know where the fob is, so cannot place their amplifying device close to it. As described, this purported hack works only if the car side is the weak one, the key fob side must be strong.

Prepackaged miniature RF amplifiers have been readily available as catalog items for decades, greatly easing the construction.

 

Good explanation. I have no idea how the signal works between the car and the fob. From what you're saying, it sounds like the bad guys boost the car signal and the fob responds.

I wonder what the max range is on the key fob signal? Could the distance be figured out by seeing how far way one could open the doors using the unlock button, or this that a different transmitter/receiver from the SKS? Kind of like my old Ford truck remote working at about a 100 feet or so.

 

As best we can assume so far, it uses the very same transmitter, saving hardware and system complexity. If it used a separate transmitter, an extremely simple and no-cost part substitution would give it a very short range to match the car side.

 

It's all coming together for me now. Thanks. I'll keep using my Faraday Bag as needed.

Cheers!