Protocol: Alice wishes to get the result of n photons through an interference circuit. She chooses m additional ‘decoy’ inputs to be orthogonal to all n. Then c

Protocol: Alice wishes to get the result of n photons through an interference circuit. She chooses m additional ‘decoy’ inputs to be orthogonal to all n. Then chooses a rotation key and performs that on all inputs before sending to bob. Bob runs through the interference circuit, returns photons to Alice. Alice de-rotates and reads the result. This works because an interference circuit is isomorphic in any polarization basis, and the decoy inputs are independently superimposed on the output. Also, the quantum part is that they are single photons, so Bob can’t read and reproduce their polarizations unless he knows the basis. Note: single photons are a probabilistic phenomenon, not simple at all to work with. The experiment can be done with A continuous wave source, and the difference would not be known unless it was attacked. Always assume, when talking about quantum photonics, that only a small number of the bits are from single photons. Statistically, the more single-bit states, the more zero-bit states. Anybody have insight into basis homomorphisms in superconducting quantum circuits?