3 ms·

I think that assumes that all the processing the key fob does internally is reliable constant-time down to the nanosecond. I don't know if that's true but my fi

I think that assumes that all the processing the key fob does internally is reliable constant-time down to the nanosecond. I don't know if that's true but my first guess is that it's doubtful.

gambiting 8y ago
Well, those chips are designed for this one purpose and nothing else - it should be possible to design them in such a way that the encryption/decryption process always ends in constant time.
- wglb 8y ago
  Keep in mind that amplitude of signal is cut by four as the distance doubles. Elapsed time is linear with distance.
- jonahrd 8y ago
  Most of these automotive chips only have timing accuracy of microseconds