I'm surprised that Americans aren't pushing to make private and secure communication a constitutional right. Will it make it harder for law enforcement to go after "bad guys"? Yes. Just as the second, fourth, and fifth amendments do today.
The 4th amendment already say that. Papers and effects cleanly expand to communication in all forms even those not imagined today.
Courts say otherwise sometimes, but they have to use twisted, convoluted reasoning that doesn't really stand up to the written letter of the constitution. Given that nothing more we can do in the constitution is immune from that either so what is the point of another amendment?
The 4th amendment grants access if a court signs a warrant. The unique challenge of encrypted communications is that there is no way to access encrypted data without a person giving up their key.
You're correct to identify "giving up the key" as the important step. Furthermore, 4A is very clear that should only happen "upon probable cause, supported by oath or affirmation, and particularly describing the place to be searched, and the persons or things to be seized." The state can't cheat by pretending it has all of this for the entire populace ahead of time. The literal text of the Constitution makes key escrow impossible.
LE doesn't need a key if they can just break the door down. So all that's needed is a key escrow system set up to broadcast when a key is accessed, so unauthorized access can be prosecuted.
The "key escrow system" contains no keys, because only a chump would give up her or his key before she or he has to give it up. As addressed above, 4A specifies very particular circumstances for that, circumstances which do not apply to most citizens.
Crypto is munitions for export purposes, I doubt you can get a ruling that it qualifies for 2A protection. The law is like that. The law can classify a thing as one thing for one purpose, and another thing for another purpose. If they want to ban crypto, they could classify it as a Schedule I drug and it'd make about as much sense as classifying it as a munition.
2A isn't upheld any more than 4A. States will just require a license for crypto and make it "may-issue". RSA will be classified an "assault algorithm" and banned in California. You'll have to pay a $200 tax stamp for each key, message capacity will be limited to 10 characters, and if your ex-wife claims you hit her then the sheriff can confiscate your hard drives until you convince a judge you didn't.
