Here's an idea

Hello,

I was thinking about how unsecure wireless remote controls are... Most remote controllers are simple one-way devices that transmit a frequency / code to a car to open it. Anyone with a wideband recorder/playback system can "listen in" and repeat the code to open your car.

My idea works very much like modern-day network logins:

1. Client (remote) sends "want to login" token
2. Server(garage/car/whatever) sends random 16-bit hash.
3. Client XORs the hash with the 16-bit login code and sends it back to server.
4. Server unhashes (XOR again) to extract code
5. Compare codes
6. If codes match, open door / whatever.

Of course, this makes for a clunki(er) remote, but it is far more secure. Simply repeating the code will have no effect at all.

Of course, if my idea is complete ********, feel free to tell me.

Cheerz,
JB

yes its a good idea.

It took me a while to comprehend what you were saying,
cos you weren't using normal language.

The remote shouldn't be much different in its effect.
I dont think it would be notice-ably affected.

Chips to do this are cheap enough.
Maybe it is already done on some cars.

It occurs to me that its only the signal from the
key-fob that is suspect.
The signal from the vehicle to the key-fob would not
be suspect.

That strikes me as an ideal situation for a 'high-encryption' one way, to a 'high-decryption' set
on the car.

Dunno ... its all getting too hi falutin' for me.
And i cant figure out where to vote ....
Its time i gave up

John

found the vote bit,
it comes up after ...

John

Now you have to have a sensitive receiver in the remote, with some processing power, in addition to the transmitter. This might be tough to fit into a key or fob.

I thought some remote keyfobs always transmitted different codes, in order to stop them being copied?. Both the transmitter and receiver use the same pseudo random sequence - so every time you operate it a different code is used.

idea is ok

yet still not secure enough and too complicated

two timers (one in remote and one in car/garage) could also do it- they produce identical keycodes every few mins. that would make the remote cheaper since it would only have to be one-way