[exprL]

How would you duplicate a wireless signal that contains an “answer” to a changing challenge (e.g. sign this message with the secret key)?

[TheLoneWolfling]

Easy. You do a relay attack.

I.e. instead of comp -> wireless -> device, you go comp -> extender <comp> -> extender <device> -> device -> extender <device> -> extender <comp> -> comp.