Re: So...
But as soon as you get a delivery method switch (optic to wire, wire to wifi, wifi to PC OS) that is compromised, they could be decoding/encoding and then passing back to you pretend content/communication.
That's true for classical information.
But you cannot have quantum cryptography that is not "end to end" (expect politicians demanding "non end-to-end quantum cryptography", similar to "decryptable crypto without backdoor" any moment now).
When transmitting the entangled photon from A to B, when C reads it "in flight", you will know it, as extracting the classical bit midway breaks the entanglement. B will obtain a garbled key, instead of bits out correlated to the bits in, there will be random bits in there. In case not all photons are read - as will be the case in any real-world channel as "bits are read" by anything on the line - you will still get a certain percentage of good bits, some heavy redundancy in the message should be helpful in that case.
Biting the hand that feeds IT
