what's still missing is encrypted stealth radio communication. something that uses a wide range of frequencies, low power with big timing windows to be indistinguishable from other things happening on air. It should look like noise and regular signals (like non-decryptable LTE packages combined with noise that could also as well just come from a power-supply)
Quantum may surpass this, as legal restrictions exist for general public broadcasting encrypted radio. What you describe probably already exists in implementation in use cases where it is legally protected and judiciously implemented.
