F4celess
Cold
I have meanwhile found out, that the reason, this adapter is so bulky, is because it contains the same audio processor, as the camera itself. And the newer gopros only accept digital audio in, not analog, as the older gopros, and as garmin cameras.
So not exactly encryption, but still not easy to make it smaller.
Interesting, that explains a lot. Though, it is still a pretty annoying way to deal with it.