Key distribution scheme for aircraft equipped with secure ADS-B IN

Abstract

We propose a new framework to verify the authenticity and integrity of Automatic Dependent Surveillance Broadcast (ADS-B) messages that extends our previous work by enabling in aircraft equipped with ADS IN technology to validate the integrity of location updates received from nearby aircraft. We include security metadata in each ADS-B message, to be used instead of the Cyclic Redundancy Check (CRC), consisting of a pair of keyed hash message authentication code (HMAC) digests. Each digest is obtained by running a HMAC algorithm with a different key which could be used to authenticate ADS-B messages at ground component and nearby aircraft. The novelty of this paper consists of our usage of a commutative group key management scheme that does not send the group key over the air, but instead provides mechanisms to update it. Given that many aircraft may join or leave the group at a given time, this protocol creates a robust mechanism with minimum overhead in maintaining keying material.