Hi. Want to install the encryption package mavlink from the pixhawk to the mission planner. For these purposes, I chose the option to insert between the PX and the raspberry antenna. PX is connected to raspberry by microUSB, antenna via UART on GPIO. To read MAVlink packets with PX I use MAVproxy, because I could not read directly from the interface. Therefore, I intercept the UDP packet, encrypt it on raspberry and transmit it to the antenna interface. Faced with this problem, telemetry is transmitted from the PX, but the team with the Mission planner in the PX are only a part. At the same time on raspberry they reach and I send them back to MAVproxy on UDP port. You can advise that it is possible to make or where to look. Or if there are other options how you can make encrypted traffic between px and mission planner. Thanks.
Since you are using mission planner, you are probably using ArduPilot and not PX4 software. Therefore, you might get more answers in the ArduPilot forum.
Thank you for helping.