Threat actors may compromise a victim spacecraft via the crosslink communications of a neighboring spacecraft that has been compromised. spacecraft in close proximity are able to send commands back and forth. Threat actors may be able to leverage this access to compromise other spacecraft once they have access to another that is nearby.
A component of cybersecurity to deny unauthorized persons information derived from telecommunications and to ensure the authenticity of such telecommunications. COMSEC includes cryptographic security, transmission security, emissions security, and physical security of COMSEC material. It is imperative to utilize secure communication protocols with strong cryptographic mechanisms to prevent unauthorized disclosure of, and detect changes to, information during transmission. Systems should also maintain the confidentiality and integrity of information during preparation for transmission and during reception. Spacecraft should not employ a mode of operations where cryptography on the TT&C link can be disabled (i.e., crypto-bypass mode). The cryptographic mechanisms should identify and reject wireless transmissions that are deliberate attempts to achieve imitative or manipulative communications deception based on signal parameters.
Leverage best practices for crypto key management as defined by organization like NIST or the National Security Agency. Leverage only approved cryptographic algorithms, cryptographic key generation algorithms or key distribution techniques, authentication techniques, or evaluation criteria. Encryption key handling should be performed outside of the onboard software and protected using cryptography. Encryption keys should be restricted so that they cannot be read via any telecommands.
Authenticate all communication sessions (crosslink and ground stations) for all commands before establishing remote connections using bidirectional authentication that is cryptographically based. Adding authentication on the spacecraft bus and communications on-board the spacecraft is also recommended.
The spacecraft should protect system components, associated data communications, and communication buses in accordance with TEMPEST controls to prevent side channel / proximity attacks. Encompass the spacecraft critical components with a casing/shielding so as to prevent access to the individual critical components.
Terminate the connection associated with a communications session at the end of the session or after an acceptable amount of inactivity which is established via the concept of operations.
Provide additional protection modes for commanding the spacecraft. These can be where the spacecraft will restrict command lock based on geographic location of ground stations, special operational modes within the flight software, or even temporal controls where the spacecraft will only accept commands during certain times.
Monitor defined telemetry points for malicious activities (i.e., jamming attempts, commanding attempts (e.g., command modes, counters, etc.)). This would include valid/processed commands as well as commands that were rejected. Telemetry monitoring should synchronize with ground-based Defensive Cyber Operations (i.e., SIEM/auditing) to create a full space system situation awareness from a cybersecurity perspective.
Utilize on-board intrusion detection/prevention system that monitors the mission critical components or systems and audit/logs actions. The IDS/IPS should have the capability to respond to threats (initial access, execution, persistence, evasion, exfiltration, etc.) and it should address signature-based attacks along with dynamic never-before seen attacks using machine learning/adaptive technologies. The IDS/IPS must integrate with traditional fault management to provide a wholistic approach to faults on-board the spacecraft. Spacecraft should select and execute safe countermeasures against cyber-attacks. These countermeasures are a ready supply of options to triage against the specific types of attack and mission priorities. Minimally, the response should ensure vehicle safety and continued operations. Ideally, the goal is to trap the threat, convince the threat that it is successful, and trace and track the attacker — with or without ground support. This would support successful attribution and evolving countermeasures to mitigate the threat in the future. “Safe countermeasures” are those that are compatible with the system’s fault management system to avoid unintended effects or fratricide on the system.
Utilize TRANSEC in order to prevent interception, disruption of reception, communications deception, and/or derivation of intelligence by analysis of transmission characteristics such as signal parameters or message externals. For example, jam-resistant waveforms can be utilized to improve the resistance of radio frequency signals to jamming and spoofing. Note: TRANSEC is that field of COMSEC which deals with the security of communication transmissions, rather than that of the information being communicated.
Detection of authentication attempts using cryptographic keys that have already been rotated or marked as no longer valid. This may indicate that threat actors are using old or compromised keys to try to access to spacecraft or C2 systems.
[x-opencti-cryptographic-key:status = 'rotated or expired']
Monitors crosslink channels for unencrypted data exchanges that could indicate improper configuration or security degradation. Typically the crosslinks are encrypted and an adversary may attempt to put crosslink into clear mode to further attacks.
[network-traffic:src_ref.value = 'crosslink' AND network-traffic:encryption_status != 'encrypted']
Monitors for abnormal increases in crosslink communication traffic, which may suggest unauthorized data transfers between spacecraft or accessing being attempted via crosslink.
[network-traffic:src_ref.value = 'crosslink' AND network-traffic:traffic_volume > 'baseline_threshold']
Monitors for crosslink communications targeting spacecraft not included in the authorized constellation network. Your spacecraft could be used as a pivot point to other spacecraft.
[network-traffic:src_ref.value = 'crosslink' AND network-traffic:dst_ref.value != 'authorized_spacecraft']
Monitors RF noise levels in GNSS or uplink bands that exceed expected thresholds, leading to safe-mode activation. This could indicate deliberate signal jamming aimed at exploiting reduced protections in safe-mode. Entering safe mode does not necessarily indicate jamming of commanding has occurred, as some spacecraft enter safe-mode after expected communication contacts with the ground are missed.
[x-opencti-rf-sensor:frequency_band IN ('gnss_band','uplink_band') AND x-opencti-rf-sensor:noise_level > 'maximum_threshold' AND x-opencti-spacecraft-status:mode = 'safe-mode']