[simne]

Quantum communications are not totally hidden. One in any case could detect some strangeness on emissions from target star.

Even encrypted communications MUST be different from space/star emissions.

What Quantum communications are, they will very early show you, that somebody hearing your quantum emissions.

And yes, if aliens will hear our cellular network, they first will see, that Earth radio emissions are just about Sun radio emissions, they will not understand content, but will see too much radio emissions from planet.

If we will use Quantum radars (lasers) to probe nearest stars, we will know very fast (speed of light), that somebody intercept emissions.

So, exists possibility, aliens already know that we looking on them (hear them), but they remain undetected, and same trick could use Earth.

Sure, aliens could use data from such probes, to make shadow shields, to not emit to sides, where detected hearing.

[weare138]

Quantum communications are not totally hidden.

True but at the same time we would have to be looking for it but we're currently mostly concentrating on radio signals.

[simne]

Ok, you are wrong. We now trying to find ANYTHING looking artificial (unnatural). This could be radio emission, light emission, infrared emission, or anything other we could detect.

Just radio emission is not enough to prove something artificial. For example, Jupiter have very powerful radio emissions, you could receive them by ordinary radio receiver.

But radio emissions are most comfortable to work with, that's why PRIVATE persons invest to this.

[simne]

Sure, but how to do this?