Secure Comms

Question 1

Analogue scrambling use

Answer 1

Can prevent casual eavesdropped, but not very secure

Question 2

Rolling code secure key fob

Answer 2

Each tiem the key fob transmits it generates a new pseudorandom coder. Codes must match to unlock.

Receiver usually checks up to 256 of the next code sequences

Question 3

Spread spectrum characteristics

Answer 3

Looks like noise and very hard to intercept

Very hard to jam as jammers usually block very large frequency ranges

Very secure since frequency hopping follows a pseudorandom sequence