SC-40(4) - Wireless Link Protection | Signal Parameter Identification

Implement cryptographic mechanisms to prevent the identification of [Assignment: organization-defined wireless transmitters] by using the transmitter signal parameters.


Informational References

ISO 27001

ID: SC-40(4)
Enhancement of : SC-40

Countermeasures Covered by Control

ID Name Description D3FEND
CM0029 TRANSEC 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. D3-MH D3-MAN D3-MENCR D3-NTA D3-DNSTA D3-ISVA D3-NTCD D3-RTA D3-PMAD D3-FC D3-CSPP D3-ANAA D3-RPA D3-IPCTA D3-NTCD D3-NTPM D3-TAAN

Space Threats Tagged by Control

ID Description

Sample Requirements

Requirement Rationale/Additional Guidance/Notes
The [organization] shall define the secure communication protocols to be used within the mission in accordance with applicable federal laws, Executive Orders, directives, policies, regulations, and standards.{PL-7,RA-5(4),SA-4(9),SA-8(18),SA-8(19),SC-8(1),SC-16(3),SC-40(4),SI-12}
The [spacecraft] shall implement relay and replay-resistant authentication mechanisms for establishing a remote connection.{SV-AC-1,SV-AC-2}{AC-3,IA-2(8),IA-2(9),SA-8(18),SC-8(1),SC-16(1),SC-16(2),SC-23(3),SC-40(4)}
The [spacecraft] shall not employ a mode of operations where cryptography on the TT&C link can be disabled (i.e., crypto-bypass mode).{SV-AC-1,SV-CF-1,SV-CF-2}{AC-3(10),SA-8(18),SA-8(19),SC-16(2),SC-16(3),SC-40(4)}
The [spacecraft] shall utilize TRANSEC.{SV-AV-1}{CP-8,RA-5(4),SA-8(18),SA-8(19),SC-8(1),SC-8(4),SC-16,SC-16(1),SC-16(2),SC-16(3),SC-40(4)} Transmission Security (TRANSEC) is used to ensure the availability of transmissions and limit intelligence collection from the transmissions. TRANSEC is secured through burst encoding, frequency hopping, or spread spectrum methods where the required pseudorandom sequence generation is controlled by a cryptographic algorithm and key. Such keys are known as transmission security keys (TSK). The objectives of transmission security are low probability of interception (LPI), low probability of detection (LPD), and antijam which means resistance to jamming (EPM or ECCM).
The [spacecraft] shall only use communication protocols that support encryption within the mission.{SA-4(9),SA-8(18),SA-8(19),SC-40(4)}

Related SPARTA Techniques and Sub-Techniques

ID Name Description
REC-0003 Gather Spacecraft Communications Information Threat actors may obtain information on the victim spacecraft's communication channels in order to determine specific commands, protocols, and types. Information gathered can include commanding patterns, antenna shape and location, beacon frequency and polarization, and various transponder information.
REC-0003.01 Communications Equipment Threat actors may gather information regarding the communications equipment and its configuration that will be used for communicating with the victim spacecraft. This includes: Antenna Shape: This information can help determine the range in which it can communicate, the power of it's transmission, and the receiving patterns. Antenna Configuration/Location: This information can include positioning, transmission frequency, wavelength, and timing. Telemetry Signal Type: Information can include timing, radio frequency wavelengths, and other information that can provide insight into the spacecraft's telemetry system. Beacon Frequency: This information can provide insight into where the spacecrafts located, what it's orbit is, and how long it can take to communicate with a ground station. Beacon Polarization: This information can help triangulate the spacecrafts it orbits the earth and determine how a satellite must be oriented in order to communicate with the victim spacecraft. Transponder: This could include the number of transponders per band, transponder translation factor, transponder mappings, power utilization, and/or saturation point.
REC-0003.02 Commanding Details Threat actors may gather information regarding the commanding approach that will be used for communicating with the victim spacecraft. This includes: Commanding Signal Type: This can include timing, radio frequency wavelengths, and other information that can provide insight into the spacecraft's commanding system. Valid Commanding Patterns: Most commonly, this comes in the form of a command database, but can also include other means that provide information on valid commands and the communication protocols used by the victim spacecraft. Valid Commanding Periods: This information can provide insight into when a command will be accepted by the spacecraft and help the threat actor construct a viable attack campaign.
REC-0003.03 Mission-Specific Channel Scanning Threat actors may seek knowledge about mission-specific communication channels dedicated to a payload. Such channels could be managed by a different organization than the owner of the spacecraft itself.
REC-0003.04 Valid Credentials Threat actors may seek out valid credentials which can be utilized to facilitate several tactics throughout an attack. Credentials may include, but are not limited to: system service accounts, user accounts, maintenance accounts, cryptographic keys and other authentication mechanisms.
REC-0005 Eavesdropping Threat actors may seek to capture network communications throughout the ground station and radio frequency (RF) communication used for uplink and downlink communications. RF communication frequencies vary between 30MHz and 60 GHz. Threat actors may capture RF communications using specialized hardware, such as software defined radio (SDR), handheld radio, or a computer with radio demodulator turned to the communication frequency. Network communications may be captured using packet capture software while the threat actor is on the target network.
REC-0005.01 Uplink Intercept Threat actors may capture the RF communications as it pertains to the uplink to the victim spacecraft. This information can contain commanding information that the threat actor can use to perform other attacks against the victim spacecraft.
REC-0005.02 Downlink Intercept Threat actors may capture the RF communications as it pertains to the downlink of the victim spacecraft. This information can contain important telemetry such as onboard status and mission data.
REC-0005.03 Proximity Operations Threat actors may capture signals and/or network communications as they travel on-board the vehicle (i.e., EMSEC/TEMPEST), via RF, or terrestrial networks. This information can be decoded to determine commanding and telemetry protocols, command times, and other information that could be used for future attacks.
REC-0005.04 Active Scanning (RF/Optical) Threat actors may interfere with the link by actively transmitting packets to activate the transmitter and induce a reply. The scan can be similar to a brute force attack, aiming to guess the used frequencies and protocols to obtain a reply.
IA-0003 Crosslink via Compromised Neighbor 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.
IA-0008 Rogue External Entity Threat actors may gain access to a victim spacecraft through the use of a rogue external entity. With this technique, the threat actor does not need access to a legitimate ground station or communication site.
IA-0008.01 Rogue Ground Station Threat actors may gain access to a victim spacecraft through the use of a rogue ground system. With this technique, the threat actor does not need access to a legitimate ground station or communication site.
IA-0008.02 Rogue Spacecraft Threat actors may gain access to a target spacecraft using their own spacecraft that has the capability to maneuver within close proximity to a target spacecraft to carry out a variety of TTPs (i.e., eavesdropping, side-channel, etc.). Since many of the commercial and military assets in space are tracked, and that information is publicly available, attackers can identify the location of space assets to infer the best positioning for intersecting orbits. Proximity operations support avoidance of the larger attenuation that would otherwise affect the signal when propagating long distances, or environmental circumstances that may present interference.
IA-0008.03 ASAT/Counterspace Weapon Threat actors may utilize counterspace platforms to access/impact spacecraft. These counterspace capabilities vary significantly in the types of effects they create, the level of technological sophistication required, and the level of resources needed to develop and deploy them. These diverse capabilities also differ in how they are employed and how easy they are to detect and attribute and the permanence of the effects they have on their target.* *https://aerospace.csis.org/aerospace101/counterspace-weapons-101
IA-0010 Exploit Reduced Protections During Safe-Mode Threat actors may take advantage of the victim spacecraft being in safe mode and send malicious commands that may not otherwise be processed. Safe-mode is when all non-essential systems are shut down and only essential functions within the spacecraft are active. During this mode, several commands are available to be processed that are not normally processed. Further, many protections may be disabled at this time.
EX-0001 Replay Replay attacks involve threat actors recording previously recorded data streams and then resending them at a later time. This attack can be used to fingerprint systems, gain elevated privileges, or even cause a denial of service.
EX-0001.01 Command Packets Threat actors may interact with the victim spacecraft by replaying captured commands to the spacecraft. While not necessarily malicious in nature, replayed commands can be used to overload the target spacecraft and cause it's onboard systems to crash, perform a DoS attack, or monitor various responses by the spacecraft. If critical commands are captured and replayed, thruster fires, then the impact could impact the spacecraft's attitude control/orbit.
EX-0011 Exploit Reduced Protections During Safe-Mode Threat actors may take advantage of the victim spacecraft being in safe mode and send malicious commands that may not otherwise be processed. Safe-mode is when all non-essential systems are shut down and only essential functions within the spacecraft are active. During this mode, several commands are available to be processed that are not normally processed. Further, many protections may be disabled at this time.
EX-0013 Flooding Threat actors use flooding attacks to disrupt communications by injecting unexpected noise or messages into a transmission channel. There are several types of attacks that are consistent with this method of exploitation, and they can produce various outcomes. Although, the most prominent of the impacts are denial of service or data corruption. Several elements of the spacecraft may be targeted by jamming and flooding attacks, and depending on the time of the attack, it can have devastating results to the availability of the system.
EX-0013.01 Valid Commands Threat actors may utilize valid commanding as a mechanism for flooding as the processing of these valid commands could expend valuable resources like processing power and battery usage. Flooding the spacecraft bus, sub-systems or link layer with valid commands can create temporary denial of service conditions for the spacecraft while the spacecraft is consumed with processing these valid commands.
EX-0013.02 Erroneous Input Threat actors inject noise/data/signals into the target channel so that legitimate messages cannot be correctly processed due to impacts to integrity or availability. Additionally, while this technique does not utilize system-relevant signals/commands/information, the target spacecraft may still consume valuable computing resources to process and discard the signal.
EX-0016 Jamming Threat actors may attempt to jam Global Navigation Satellite Systems (GNSS) signals (i.e. GPS, Galileo, etc.) to inhibit a spacecraft's position, navigation, and/or timing functions.
EX-0016.03 Position, Navigation, and Timing (PNT) Threat actors may attempt to jam Global Navigation Satellite Systems (GNSS) signals (i.e. GPS, Galileo, etc.) to inhibit a spacecraft's position, navigation, and/or timing functions.
EX-0016.01 Uplink Jamming An uplink jammer is used to interfere with signals going up to a satellite by creating enough noise that the satellite cannot distinguish between the real signal and the noise. Uplink jamming of the control link, for example, can prevent satellite operators from sending commands to a satellite. However, because the uplink jammer must be within the field of view of the antenna on the satellite receiving the command link, the jammer must be physically located within the vicinity of the command station on the ground.* *https://aerospace.csis.org/aerospace101/counterspace-weapons-101
EX-0016.02 Downlink Jamming Downlink jammers target the users of a satellite by creating noise in the same frequency as the downlink signal from the satellite. A downlink jammer only needs to be as powerful as the signal being received on the ground and must be within the field of view of the receiving terminal’s antenna. This limits the number of users that can be affected by a single jammer. Since many ground terminals use directional antennas pointed at the sky, a downlink jammer typically needs to be located above the terminal it is attempting to jam. This limitation can be overcome by employing a downlink jammer on an air or space-based platform, which positions the jammer between the terminal and the satellite. This also allows the jammer to cover a wider area and potentially affect more users. Ground terminals with omnidirectional antennas, such as many GPS receivers, have a wider field of view and thus are more susceptible to downlink jamming from different angles on the ground.* *https://aerospace.csis.org/aerospace101/counterspace-weapons-101
EX-0014 Spoofing Threat actors may attempt to spoof the various sensor and controller data that is depended upon by various subsystems within the victim spacecraft. Subsystems rely on this data to perform automated tasks, process gather data, and return important information to the ground controllers. By spoofing this information, threat actors could trigger automated tasks to fire when they are not needed to, potentially causing the spacecraft to behave erratically. Further, the data could be processed erroneously, causing ground controllers to receive incorrect telemetry or scientific data, threatening the spacecraft's reliability and integrity.
PER-0005 Valid Credentials Threat actors may seek out valid credentials which can be utilized to maintain persistent access to the spacecraft or related C2 systems and facilitate additional tactics throughout an attack. Credentials may include, but are not limited to: system service accounts, user accounts, maintenance accounts, cryptographic keys and other authentication mechanisms.
DE-0002 Prevent Downlink Threat actors may target the downlink connections to prevent the victim spacecraft from sending telemetry to the ground controllers. Telemetry is the only method in which ground controllers can monitor the health and stability of the spacecraft while in orbit. By disabling this downlink, threat actors may be able to stop mitigations from taking place.
DE-0002.02 Jam Link Signal Threat actors may overwhelm/jam the downlink signal to prevent transmitted telemetry signals from reaching their destination without severe modification/interference, effectively leaving ground controllers unaware of vehicle activity during this time. Telemetry is the only method in which ground controllers can monitor the health and stability of the spacecraft while in orbit. By disabling this downlink, threat actors may be able to stop mitigations from taking place.
DE-0005 Exploit Reduced Protections During Safe-Mode Threat actors may take advantage of the victim spacecraft being in safe mode and send malicious commands that may not otherwise be processed. Safe-mode is when all non-essential systems are shut down and only essential functions within the spacecraft are active. During this mode, several commands are available to be processed that are not normally processed. Further, many protections (i.e. security features) may be disabled at this time which would ensure the threat actor achieves evasion.
DE-0011 Valid Credentials Threat actors may utilize valid credentials to conduct an attack against a spacecraft or related system as a means to conceal their activity. Credentials may include, but are not limited to: system service accounts, user accounts, maintenance accounts, cryptographic keys and other authentication mechanisms.
LM-0003 Constellation Hopping via Crosslink Threat actors may attempt to command another neighboring spacecraft via crosslink. spacecraft in close proximity are often able to send commands back and forth. Threat actors may be able to leverage this access to compromise another spacecraft.
LM-0007 Valid Credentials Threat actors may utilize valid credentials move laterally across spacecraft subsystems, communication buses, or additional spacecraft in a constellation. Credentials may include, but are not limited to: system service accounts, user accounts, maintenance accounts, cryptographic keys and other authentication mechanisms.
EXF-0001 Replay Threat actors may exfiltrate data by replaying commands and capturing the telemetry or payload data as it is sent down. One scenario would be the threat actor replays commands to downlink payload data once the spacecraft is within certain location so the data can be intercepted on the downlink by threat actor ground terminals.
EXF-0002 Side-Channel Attack Threat actors may use a side-channel attack attempts to gather information by measuring or exploiting indirect effects of the spacecraft. Information within the spacecraft can be extracted through these side-channels in which sensor data is analyzed in non-trivial ways to recover subtle, hidden or unexpected information. A series of measurements of a side-channel constitute an identifiable signature which can then be matched against a signature database to identify target information, without having to explicitly decode the side-channel.
EXF-0002.03 Traffic Analysis Attacks In a terrestrial environment, threat actors use traffic analysis attacks to analyze traffic flow to gather topological information. This traffic flow can divulge information about critical nodes, such as the aggregator node in a sensor network. In the space environment, specifically with relays and constellations, traffic analysis can be used to understand the energy capacity of spacecraft node and the fact that the transceiver component of a spacecraft node consumes the most power. The spacecraft nodes in a constellation network limit the use of the transceiver to transmit or receive information either at a regulated time interval or only when an event has been detected. This generally results in an architecture comprising some aggregator spacecraft nodes within a constellation network. These spacecraft aggregator nodes are the sensor nodes whose primary purpose is to relay transmissions from nodes toward the ground station in an efficient manner, instead of monitoring events like a normal node. The added functionality of acting as a hub for information gathering and preprocessing before relaying makes aggregator nodes an attractive target to side channel attacks. A possible side channel attack could be as simple as monitoring the occurrences and duration of computing activities at an aggregator node. If a node is frequently in active states (instead of idle states), there is high probability that the node is an aggregator node and also there is a high probability that the communication with the node is valid. Such leakage of information is highly undesirable because the leaked information could be strategically used by threat actors in the accumulation phase of an attack.
EXF-0003 Eavesdropping Threat actors may seek to capture network communications throughout the ground station and communication channel (i.e. radio frequency, optical) used for uplink and downlink communications
EXF-0003.01 Uplink Intercept Threat actors may target the uplink connection from the victim ground infrastructure to the target spacecraft in order to exfiltrate commanding data. Depending on the implementation (i.e., encryption) the captured uplink data can be used to further other attacks like command link intrusion, replay, etc.
EXF-0003.02 Downlink Intercept Threat actors may target the downlink connection from the victim spacecraft in order to exfiltrate telemetry or payload data. This data can include health information of the spacecraft or mission data that is being collected/analyzed on the spacecraft. Downlinked data can even include mirrored command sessions which can be used for future campaigns or to help perpetuate other techniques.
EXF-0004 Out-of-Band Communications Link Threat actors may attempt to exfiltrate data via the out-of-band communication channels. While performing eavesdropping on the primary/second uplinks and downlinks is a method for exfiltration, some spacecrafts leverage out-of-band communication links to perform actions on the spacecraft (i.e., re-keying). These out-of-band links would occur on completely different channels/frequencies and often operate on separate hardware on the spacecraft. Typically these out-of-band links have limited built-for-purpose functionality and likely do not present an initial access vector but they do provide ample exfiltration opportunity.
EXF-0010 Payload Communication Channel Threat actors can deploy malicious software on the payload(s) which can send data through the payload channel. Payloads often have their own communication channels outside of the main TT&C pathway which presents an opportunity for exfiltration of payload data or other spacecraft data depending on the interface and data exchange.