John Paul Golick

A rule that will not become effective for twelve years should include provisions for technology advancement. Specifically, the security considerations used during the development of existing solutions, such as 1090ES and UAT, may need to be reconsidered in the light of more recent or developing technologies. Security should not be considered only a military concern: As the NAS begins to rely on ADS-B functions, these functions become a critical component of the NAS and the unanticipated loss of these functions adversely affect the safety and reliability of air transportation. While unintentional interference may be historically rare in the U.S., it should be noted that, historically, dependent systems have not been relied on. Making broadcasts from dependent systems a critical component of the transportation infrastructure greatly increases the potential disruption that interference can cause. The prevalence of malicious activities on the Internet should inform us that all forms of communication can be affected by malicious parties. Malicious parties may make transmissions: that confuse ATC about which aircraft are participating in the ADS-B system; that cause the appearance that a current participant is malfunctioning; that cause a current participant to take inappropriate actions; that saturate the communications channel, denying access to legitimate users; that otherwise interfere with operation of current legitimate participants. Malicious parties may also monitor transmissions of a participating aircraft to obtain information used to harm that aircraft. Although the proposal already includes the registration of legitimate ADS-B units and closed user groups can be part of a security solution, the proposal remains insecure and subject to interference or use by malicious parties. The proposal also lacks provisions for preventing or mitigating such malicious activities. Because the ADS-B system is widely distributed, the users who operate the ADS-B units must be included in the plans for physical and operational security of those units. Although normal operation of ADS-B may improve the efficiency and capacity of the NAS, the ADS-B system may also introduce new security weaknesses, and the ADS-B system can improve safety only in the absence of both malicious and unintentional interference.