Developed and integrated a security-focused MAVLink message signing feature for the PX4/PX4-Autopilot repository, enhancing message authenticity and integrity within embedded systems. The solution, implemented in C++, introduced runtime configurability and secure key management by storing signing keys on the SD card and persisting parameters across sessions. The work included designing a robust initialization process to ensure signing activates only when properly configured, as well as updating message decoding and setup flows for seamless protocol integration. Extensive updates to dependencies and user-facing documentation in Markdown supported safe, scalable deployment, reflecting a thorough approach to security implementation and maintainability in MAVLink communications.