A method for encrypting communications between two aircraft (105, 110) on the ground at an airport, comprising the step of: coupling each aircraft to a ground network; wherein the ground network comprises a broadband over power line communications network (120, 125); characterized by the steps of: initiating a mutually authenticated communications channel between each aircraft via the ground network; establishing a shared pairwise key at each aircraft; and transmitting data from one aircraft to the other aircraft, the data encrypted using the shared pairwise key at each aircraft, wherein the establishing step is performed by the steps of: transmitting a first test message from a first of the two aircraft to a second of the two aircraft, identifying, at the second of the two aircraft, a first channel state based on receipt of the first test message, generating a first shared pairwise key based on the first channel state at the second of the two aircraft; transmitting a second test message from the second of the two aircraft to the first of the two aircraft, identifying, at the first of the two aircraft, a second channel state based on receipt of the second test message, and generating a second shared pairwise key based on the second channel state at the first of the two aircraft. coupling each aircraft to a ground network; wherein the ground network comprises a broadband over power line communications network (120, 125); characterized by the steps of: initiating a mutually authenticated communications channel between each aircraft via the ground network; establishing a shared pairwise key at each aircraft; and transmitting data from one aircraft to the other aircraft, the data encrypted using the shared pairwise key at each aircraft, wherein the establishing step is performed by the steps of: transmitting a first test message from a first of the two aircraft to a second of the two aircraft, identifying, at the second of the two aircraft, a first channel state based on receipt of the first test message, generating a first shared pairwise key based on the first channel state at the second of the two aircraft; transmitting a second test message from the second of the two aircraft to the first of the two aircraft, identifying, at the first of the two aircraft, a second channel state based on receipt of the second test message, and generating a second shared pairwise key based on the second channel state at the first of the two aircraft. initiating a mutually authenticated communications channel between each aircraft via the ground network; establishing a shared pairwise key at each aircraft; and transmitting data from one aircraft to the other aircraft, the data encrypted using the shared pairwise key at each aircraft, wherein the establishing step is performed by the steps of: transmitting a first test message from a first of the two aircraft to a second of the two aircraft, identifying, at the second of the two aircraft, a first channel state based on receipt of the first test message, generating a first shared pairwise key based on the first channel state at the second of the two aircraft; transmitting a second test message from the second of the two aircraft to the first of the two aircraft, identifying, at the first of the two aircraft, a second channel state based on receipt of the second test message, and generating a second shared pairwise key based on the second channel state at the first of the two aircraft. transmitting a first test message from a first of the two aircraft to a second of the two aircraft, identifying, at the second of the two aircraft, a first channel state based on receipt of the first test message, generating a first shared pairwise key based on the first channel state at the second of the two aircraft; transmitting a second test message from the second of the two aircraft to the first of the two aircraft, identifying, at the first of the two aircraft, a second channel state based on receipt of the second test message, and generating a second shared pairwise key based on the second channel state at the first of the two aircraft.