Car Alarm Blocker - are these available?

Dark Rabbit

A neighbour's car was broken into recently. There is no forced entry evident on the car so I thought car must have been left unlocked (which I have done occasionally too). I was intrigued when my neighbour told me that car thieves have a device that can block the signal when you remote lock you car. Is this a real thing now?

5500

Yes it is and it's been around for many years now. It's just an RF jammer, here's a video to give you an idea of them

https://www.youtube.com/watch?v=SNhtpCKMLBY

Irish Steve

Blockers are indeed a problem, and an equally big problem are the devices that can capture the signal from a key fob and replicate it at a later time, it is completely feasible to have a device capture the code used in (say) the supermarket car park, follow the owner home to find out where the car is to be found later, and then return later and use the device to gain access to the vehicle.

Some newer locking systems use a randomiser system that can defeat these piggy back devices, but the reality is that the modern "keyless" concept is not as secure as having to have a physical key to unlock the steering lock. That said, if you've got access to the vehicle without the alarm sounding, it doesn't take that long to disable the steering lock if there's no danger of being disturbed.

All remote central locking systems use rolling codes unless it's from the 80's.
So its not just a case of coping the signel and Bob's your uncle.
I don't know about keyless entry but it seems weak.