content: I had a strong feeling I didn't discover anything new, but it'd be cool to popularize this in the form of an app or something. Its such a simple idea. Simply download a dictionary pdf and assign X amount ( millions) of randomly generated numbers to each word in the English language. The user would type in plain text and the app would convert the words to the corresponding numbers.  " Hi there" becomes 1834920402 - 38442674939. The receiving device  already knows what numbers correspond to each word. So it knows that 1834920402 - 38442674939 means " hi there". There's no way to break this. Now to be safe you'd want to make sure that the device didn't have any external access to it. No BT, WiFi, nothing. You'd also want to use a faraday cage ( special plastic bag) to prevent against van-eck like attacks. Then you'd  wire-transfer the data to another device which would transmit/receive the data.