Ever wondered if a quantum key exchange could slip past a watchdog? I’ve found a trick that hides the exchange in a photon’s phase. Think you can spot the flaw?

If the watchdog is a homodyne, you need to disguise the shift itself, not just hide the key. Think binary masking, use a vacuum sideband or flip the basis after the pulse leaves the transmitter. The phase stays a random variable until it’s measured, but you can entangle it with a decoy that only you know the mapping for. It’s like sending a ghost in a coat of many colours – the watchdog sees a colour, but never knows which coat hides the true one. Try that, and keep an eye on the timing jitter – that’s where the trick lives.