Hi Raspberry Pi Community,
I would like to use radio remote’s control to trigger an events on my Raspberry pi.
I guess I’ll go with 433Mhz as I believe they are the most common available ?
So I will need a 433Mhz RX/TX Module to connect on the GPIO, so far I get it…
But how properly secure the communication between those remotes and the RPI to avoid any anyone to sniff the transmitting and replay it. In other words spoof it.
Wubba Lubba dub-dub…
Might be a good use for PGP. The signal can be snooped and spoofed, but the messages should be end-to-end encrypted.
Only problem with just using just pgp is that the signal would be vulnerable to a replay attack. I feel like a rolling code that’s encrypted using PGP might be the way so that the replay attack part is gotten rid of.
All that’s to say, there’s probably some technical paper that details the best way to set up a system like this.
Could it only accept serialized messages? Once it’s received a message, never accept the same exact message again.
I think that’s the whole point of the rolling code, no?
Well then you’d have to keep track of all messages recieved. An easier option might just be to sign the current system time, make sure the clocks are synchronized, and accept a +/- 1 second wiggle
Wouldn’t it just need to know which is the highest message number it has seen? And then don’t accept that one or any lower ever again?
If the count is within the encrypted message, no one can spoof anything higher.
Oh fair good point