Comment by reaperducer
8 hours ago
I have a device with a camera and a touch-screen that only uses capacitive charging. I type a message. Bytes are encrypted. I hit send. QR codes flash on my screen. I use my PC or my normal phone to receive the encrypted bytes, and transmit them to you. You have the same device. You have your PC or phone flash encrypted QR codes. You use your device to receive, and then decrypt.
Congratulations. You just invented IrDA: https://en.wikipedia.org/wiki/IrDA
I specifically want this device to have no input or output hardware that could be used without my knowledge. IrDA could absolutely be used without my knowledge.