Data Manipulation: Transmitted Data Manipulation

an attacker can modify transmitted data, jamming or overpowering the original signal and retransmitting a modified copy to the receiver, to command a spacecraft or to lead the system owner to erroneous decision. An attacker can target the telecommands sent from a GS, to change the spacecraft behavior, or he can tamper the telemetry sent from a spacecraft to change the GS received data. Intercepted and modified range measurement sent to the control center could lead to erroneous range measurements, which could cause incorrect trajectory determination. Mitigations are redundancy/diversity to protect the source and authentication to protect the message. To protect the data source, a star sensor offers ah high level of reliability. An attacker can also target the payload data sent from or to a spacecraft. To mitigate this, Navigation Message Authentication (NMA) uses symmetric/asymmetric key encryption to provide authenticity and integrity of the navigation data to the receiver.