@UrbanCityCowboy I would love to know more about how you used it and other ways that can be used. What came to my mind was to take down a printed advertisement from a community bulletin board, change the QR code for their website to an encrypted QR code then place the new copy back on the board so someone else could retrieve that message at a later time without broadcasting any metadata over monitored networks. This would make it much more difficult to know who is talking to each other.