It’s important to note here, that in Germany (at least, the region where I live) you will fail the practical driving exam if you don’t stop at a crosswalk with any pedestrian within about 5 meters, unless they are actively walking away from it.
I think overall German driver’s education is significantly better (and much more expensive) than in the US.
Depending on the language, there might exist an automated tool for generating those kinds of diagrams from code.
You may want to look into amateur radio (or you might not, it needs a licence after all).
I don’t really have any recommendations for you, but I would suggest you crosspost this to !amateur_radio@lemmy.radio
amateur radio was illegal to encrypt
Amateur radio is still illegal to encrypt (with some exceptions for controlling satelites), because private communication isn’t the point of amateur radio.
Besides, (in most countries) there are some topics that are illegal to talk over amateur radio about, mainly stuff like politics and religion. You’re also not allowed to offer telecommunication services (i.e. pass messages on for others). Enforcing those sorts of laws would be impossible with encryption.
But to answer your question: I think we probably wouldn’t have had an internet. Authoritarian regimes thrive on stability and maintaining the status quo, I think someone high up would have quickly decided that developing that sort of tech is too risky.
One thing I don’t like about the “master key” metaphor: I do lockpicking as a hobby. And locks built for a master key are easier to pick, because you can open them with two keys. It seems kinda obvious when you think about it. (You gotta be careful when picking mastered locks though, the master wafers can fall into the keyway and permanently destroy the lock.)