From what I understood, one of the advantages of quantum communication is that one can (mathematically/physically) prove that the quantum communication/message has not been intercepted/tampered with. (I believe this proof relates to the no-cloning theorem).
However, I would like to ask: Is it possible (in theory) for Alice and Bob to communicate using quantum communication techniques without anyone being able to detect that they communicate? And if yes, is there a cost to such a level of security?
- I assume Alice and Bob are able to meet physically and undetected to set up some key/pairing/initial encryption. (I am not sure whether this is required, yet I assume so.)