Thirty years ago, maybe…

It is not very often that I receive a chain e-mail that is as easy to disprove as this one, and because it is Sunday afternoon, I’m feeling lazy, and I want to go home and have a braai and a few glasses of amarula I’m going to be very lazy and just give you the basics here (but you understand, right?).

The chain e-mail:

Hi Johan

Kyk hier nuwe manier hoe om ons motors te steel!

(Translated by SD as “Check out this new method of stealing our cars).

I locked my car. As I walked away I heard my car door unlock. I went back and locked my car again three times .. Each time, as soon as I started to walk away, I would hear it unlock again!! Naturally alarmed, I looked around and there were two guys sitting in a car in the fire lane next to the store. They were obviously watching me intently, and there was no doubt they were somehow involved in this very weird situation. I quickly chucked the errand I was on, jumped in my car and sped away.. I went straight t o the police station, told them what had happened, and found out I was part of a new, and very successful, scheme being used to gain entry into cars. Two weeks later, my friend’s son had a similar happening….
While traveling, my friend’s son stopped at a roadside rest to use the bathroom. When he came out to his car less than 4-5 minutes later, someone had gotten into his car and stolen his cell phone, laptop computer, GPS navigator, briefcase… name it. He called the police and since there were no signs of his car being broken into, the police told him he had been a victim of the latest robbery tactic — there is a device that robbers are using now to clone your security code when you lock your doors on your car using your key-chain locking device..

They sit a distance away and watch for their next victim. They know you are going inside of the store, restaurant, or bathroom and that they now have a few minutes to steal and run. The police officer said to manually lock your car door-by hitting the lock button inside the car — that way if there is someone sitting in a parking lot watching for their next victim, it will not be you.

When you hit the lock button on your car upon exiting, it does not send the security code, but if you walk away and use the door lock on your key chain, it sends the code through the airwaves where it can be instantly stolen.
This is very real.

Be wisely aware of what you just read and please pass this note on. Look how many times we all lock our doors with our remote just to be sure we remembered to lock them — and bingo, someone has our code….and whatever was in our car.

Snopes Approved –.Please share with everyone you know

Ok, so apart from telling you that the attempt to spread fear is a blatant red-flag, as well as the completely unprovable testimonials which are about as reliable as an ice tent in the kalahari dessert, I’m simply going to have a look at the facts here. If this method were being used in the 1970’s when automatic entry devices were (literally) made up of a couple  of transistors and a radio transmitter, this “new method might work”. That’s because back in the days of polyester bell bottoms remote entry systems were crude and unsophisticated and analogue. Some nasty bad guy might have been able to detect the frequency of your car’s remote and unlock it when you were gone by transmitting the correct frequency back at your car’s receiver.

Luckily for us, modern technology has made things a little bit more difficult. I found this fantastic, simple explanation on “How Stuff Works“:

Modern Security

With the remote keyless-entry systems that you find on cars today, security is a big issue. If people could easily open other people’s cars in a crowded parking lot at the mall, it would be a real problem. And with the proliferation of radio scanners, you also need to prevent people from “capturing” the code that your transmitter sends. Once they have your code, they can simply re-transmit it to open your car.

The photo below shows you the guts of a typical key-ring controller for a modern car:

Inside the car controller

You can see that everything has been miniaturized. There is a small chip that creates the code that gets transmitted, and the small silver can (about the size of a split pea) is the transmitter.

The controller chip in any modern controller uses something called a hopping code or a rolling code to provide security. For example, if you read this PDF, it describes a system that uses a 40-bit rolling code. Forty bits provide 240 (about 1 trillion) possible codes. Here’s how it works:

  • The transmitter’s controller chip has a memory location that holds the current 40-bit code. When you push a button on your key fob, it sends that 40-bit code along with a function code that tells the car what you want to do (lock the doors, unlock the doors, open the trunk, etc.).

  • The receiver’s controller chip also has a memory location that holds the current 40-bit code. If the receiver gets the 40-bit code it expects, then it performs the requested function. If not, it does nothing.

  • Both the transmitter and the receiver use the same pseudo-random number generator. When the transmitter sends a 40-bit code, it uses the pseudo-random number generator to pick a new code, which it stores in memory. On the other end, when the receiver receives a valid code, it uses the same pseudo-random number generator to pick a new one. In this way, the transmitter and the receiver are synchronized. The receiver only opens the door if it receives the code it expects.

  • If you are a mile away from your car and accidentally push the button on the transmitter, the transmitter and receiver are no longer synchronized. The receiver solves this problem by accepting any of the next 256 possible valid codes in the pseudo-random number sequence. This way, you (or your three-year-old child) could “accidentally” push a button on the transmitter up to 256 times and it would be okay — the receiver would still accept the transmission and perform the requested function. However, if you accidentally push the button 257 times, the receiver will totally ignore your transmitter. It won’t work anymore.

So, what do you do if your three-year-old child DOES desynchronize your transmitter by pushing the button on it 300 times, so that the receiver no longer recognizes it? Most cars give you a way toresynchronize. Here is a typical procedure:

  • Turn the ignition key on and off eight times in less than 10 seconds. This tells the security system in the car to switch over to programming mode.
  • Press a button on all of the transmitters you want the car to recognize. Most cars allow at least four transmitters.
  • Switch the ignition off.

Given a 40-bit code, four transmitters and up to 256 levels of look-ahead in the pseudo-random number generator to avoid desynchronization, there is a one-in-a-billion chance of your transmitter opening another car’s doors. When you take into account the fact that all car manufacturers use different systems and that the newest systems use many more bits, you can see that it is nearly impossible for any given key fob to open any other car door.

You can also see that code capturing will not work with a rolling code transmitter like this. Older garage door transmitters sent the same 8-bit code based on the pattern set on the DIP switches. Someone could capture the code with a radio scanner and easily re-transmit it to open the door. With a rolling code, capturing the transmission is useless. There is no way to predict which random number the transmitter and receiver have chosen to use as the next code, so re-transmitting the captured code has no effect. With trillions of possibilities, there is also no way to scan through all the codes because it would take years to do that.

Please read the final paragraph again (I couldn’t have said it better myself). And now delete the silly chain e-mail. Whenever you get an e-mail like this, please take a few minutes to verufy the facts before you send it on to your friends.  Don’t take the e-mail’s author’s word for it when they append “Snopes Approved” to the end of the story. The chances are that they are trying to stop you from doing any investigating because they know that is a load of bolloks!


6 responses to “Thirty years ago, maybe…

  1. Pingback: A new Method to steal from your car or truck·

  2. My problem is that my car remote also unlocks my neighbors car, they are both the same make but different models and 3 years apart in ages. The strange think is that it has just started to happen after about 4 1/2 years. Now when I go out and unlock my car – car unlocks and I drive away leaving my neighbours car unlocked it does lock it self after few minutes but it is not very comforting it only happens with my remote the neighbours car remote does not unlock mine – does any one have any ideas of a fix or is it a garage job – it is a pain – thanks

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