This article presents our survey work on Unmanned Aerial Vehicle (UAV) communication security for UAV Traffic Management (UTM) safety [1]. A majority of UAV missions require flying through public airspace. Airspace management is a sector with very high safety standards, as can be seen with commercial civil aviation. Reliable communication links between aircraft, their pilots and UTM systems are necessary to safely carry out these missions. Several security properties have to be provided in order to ensure a safe traffic. Current cryptographic standards used over the internet are not suitable to Unmanned Aerial System (UAS), mainly due to their computational complexity. The survey discusses every communication link and assesses the security needs in order to enable a safe traffic management. We then present and discuss several research works providing the
required properties using cryptographic primitives. In particular, authenticated key exchange protocols specifically developed for constrained systems are compared and evaluated as solutions for UAS security. We also discuss symmetric encryption alternatives to the AES algorithm as well as works to secure current UTM protocols such as ADS-B and RemoteID. The analysis reveals a lack of signature solutions, the need for the development of a
complete secure architecture able to provide authentication and integrity and a need for post-quantum lightweight solutions. We then present our current work which focuses on implementing post-quantum signature standards for UAS.