We investigate security of ADS-B system and propose a framework composed of two solutions that would require minimal change to the existing system. The investigation focuses on providing an encrypted ADS-B system that provides confidentiality, availability, and integrity while requiring minimal changes to the existing ADS-B specification. The proposed framework consisting of two solutions is envisioned to be implemented through software updates while providing backwards compatibility. The most challenging requirement during this study was to work within the constraints of the existing ADS-B system
