41–50 of 102 posts
> "I thought it was some kind of alien phenomena." Any sufficiently advanced technology is indistinguishable from magic. For some (a lot?) of people, keyless entry seems still to be an advanced technology.
I had a 40 year old oscilloscope open (Tek 465) on my desk a few years back when the in laws came round and it was like watching the monkeys around the monolith in 2001.
There is nothing 'mysterious' about this, this is just how radios work. Neither does it have to be malicious. Most car key fobs work in the 433MHz range, if there is something in the area transmitting at said frequency, it will cause the relatively weak signals from keys fobs to be blocked. This it why we have electromechanical compatibility (EMC) certification for any electrical devices being sold. With the market b…
Still sounds pretty mysterious to me. This kind of event is rare, and the source of the interference is (currently) a mystery. I’d love to pop by with a HackRF and directional antenna if I lived anywhere near-by!
Even at my car dealership this is a common problem. A couple hundred cars with the same keyless entry system parked in the same lot. All those cars are actively scanning for their key fob, which causes all sorts of RF collisions. I've gotten used to having to use my physical key when picking up my car at the dealership.
https://electronics.stackexchange.com/questions/86895/how-el...
It'll be someone using a 'jam, listen, and replay' device to unlock and start keyless cars so they can drive them to a port and steal them. Pretty much every week a car is stolen this way from my street. I now always take the engine management fuse out of the fusebox when parking my car so at least the car can't start when a thief pulls this... They tried anyway though!
Curious as to how such a device would recover the original signal while it’s broadcasting a stronger signal to jam the frequency. Also, if you don’t mind, which city/country are you in? It seems insane that this is a regular problem happening in the same location and law enforcement doesn’t catch on.
Of course, the strategy I've heard outlined is to jam and record one rolling code, then a second one, then to replay the first code so the fob holder sees the system respond to their button press but the attacker has a ready-to-use code. If people are seeing their cars failing to unlock, it's not that specific attack.
[1] Page 63 of https://samy.pl/defcon2015/2015-defcon.pdf
If so, could one of those be repurposed? I suspect they have fairly wideband scanners.
Last time this happened in the UK it was a push to call for assistance system that got stuck on, also at 433mhz. It’ll be the same here.
A Tesco spokesperson said its garages had a system which allowed disabled drivers to contact a member of staff in the kiosk using a special key fob to call for assistance.
This used a short signal which came on briefly to alert staff that someone needed help. But at Clifton Moor this had become jammed on and had blocked the remote central locking and ignition frequencies used by some cars.