Securing air-ground communications

As Air Traffic Control Systems (ATC) move from a voice only environment to one in which clearances are issued via data link, there is a risk that an unauthorized entity may attempt to masquerade as either the pilot or controller. In order to protect against this and related attacks, air-ground communications must be secured. The challenge is to add security in an environment in which bandwidth is limited. This paper, which is derived from draft guidance material on security for the Aeronautical Telecommunications Network (ATN) begins with a basic introduction to the relevant security concepts of security threats, security services and security mechanisms. Security mechanisms are further examined by first presenting the fundamental building blocks of symmetric encipherment, asymmetric encipherment, and hash functions and then describing how the fundamental techniques may be combined to form cryptographic schemes. With this background, this paper next describes the cryptographic schemes defined for use in the (ATN) their specific application in securing controller-pilot data link communications. This paper also briefly describes how the ATN cryptographic schemes can be used to secure the exchange of other Air Traffic Services Communications (ATSC) applications, and non-ATSC applications, including Airline Operational Control (AOC) applications