Communication Physical Medium

Establish alternate physical medium for networking based on threat model/environment. For example, fiber optic cabling is commonly perceived as a better choice in lieu of copper for mitigating network security concerns (i.e., eavesdropping / traffic flow analysis) and this is because optical connections transmit data using light, they don’t radiate signals that can be intercepted.

Sources

https://www.timbercon.com/resources/blog/fiber-optics-a-more-secure-solution/

NIST Rev5 Controls

D3FEND Techniques

D3FEND Artifacts

ISO 27001

NASA Best Practice Guide

MI-ARCH-01

ESA Space Shield Mitigation

None

Related MITRE EMB3D Mitigations

No related MITRE EMB3D Mitigations

Related CSF 2.0

Related BSI Security Measures

BM28
BM29
BM51
BM53

ID: CM0071

Tier: III

Onboard SV CM Ground CM

Created: 2022/12/08

Last Modified: 2023/10/17

Techniques Addressed by Countermeasure

ID		Name	Description
EXF-0002		Side-Channel Exfiltration	Information is extracted not by reading files or decrypting frames but by observing physical or protocol byproducts of computation, power draw, electromagnetic emissions, timing, thermal signatures, or traffic patterns. Repeated measurements create distinctive fingerprints correlated with internal states (key use, table loads, parser branches, buffer occupancy). Matching those fingerprints to models or templates yields sensitive facts without direct access to the protected data. In space systems, vantage points span proximity assets (for EM/thermal), ground testing and ATLO (for direct probing), compromised on-board modules that can sample rails or sensors, and remote observation of link-layer timing behaviors.
	.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-0004		Out-of-Band Communications Link	Some missions field secondary links, separate frequencies and hardware, for limited, purpose-built functions (e.g., rekeying, emergency commanding, beacons, custodial crosslinks). Adversaries co-opt these channels as covert data paths: embedding content in maintenance messages, beacon fields, or low-rate housekeeping; initiating vendor/service modes that carry file fragments; or switching to contingency profiles that bypass normal routing and monitoring. Because these paths are distinct from the main TT&C and may be sparsely supervised, they provide discreet avenues to move data off the spacecraft or to external relays without altering the primary link’s traffic patterns.

Space Threats Addressed by Countermeasure

ID	Description
SV-AC-5	Proximity operations (i.e., grappling satellite)
SV-AC-6	Three main parts of S/C. CPU, memory, I/O interfaces with parallel and/or serial ports. These are connected via busses (i.e., 1553) and need segregated. Supply chain attack on CPU (FPGA/ASICs), supply chain attack to get malware burned into memory through the development process, and rogue RTs on 1553 bus via hosted payloads are all threats. Security or fault management being disabled by non-mission critical or payload; fault injection or MiTM into the 1553 Bus - China has developed fault injector for 1553 - this could be a hosted payload attack if payload has access to main 1553 bus; One piece of FSW affecting another. Things are not containerized from the OS or FSW perspective;

Sample Requirements

SPARTA ID	Requirement	Rationale/Additional Guidance/Notes
SPR-3	The [spacecraft] shall enforce approved authorizations for controlling the flow of information within the platform and between interconnected systems so that information does not leave the platform boundary unless it is encrypted. Flow control shall be implemented in conjunction with protected processing domains, security‑policy filters with fully enumerated formats, and a default‑deny communications baseline.{SV-AC-6}{AC-3(3),AC-3(4),AC-4,AC-4(2),AC-4(6),AC-4(21),CA-3,CA-3(6),CA-3(7),CA-9,IA-9,SA-8(19),SC-8(1),SC-16(3)}	Spacecraft operate in constrained and deterministic environments where uncontrolled data flows can enable data exfiltration, cross-domain leakage, or lateral movement between subsystems. Enforcing approved authorizations with enumerated formats and a default-deny posture ensures only explicitly permitted communications occur. Encryption enforcement at platform boundaries prevents unauthorized disclosure of telemetry or state information.
SPR-11	The [spacecraft] encryption key handling shall be handled outside of the onboard software and protected using cryptography.{SV-AC-1,SV-AC-3}{AC-17(6),CM-3(6),SA-8(19),SA-9(6),SC-8(1),SC-12,SC-28(1),SC-28(3)}	Key management separated from modifiable flight software reduces exposure to software compromise. If keys are accessible to onboard applications, malicious code could extract or misuse them. Hardware-anchored or externally managed key handling reduces persistence risk. This supports trust-chain assurance and mitigates firmware-level compromise.
SPR-12	The [spacecraft] encryption keys shall be restricted so that the onboard software is not able to access the information for key readout.{SV-AC-1,SV-AC-3}{AC-17(6),CM-3(6),SA-8(19),SA-9(6),SC-8(1),SC-12,SC-28(3)}	Even privileged software must not be able to retrieve plaintext keys. Preventing readout mitigates malware harvesting and insider misuse. Key usage should be mediated through cryptographic modules rather than direct exposure. This enforces least privilege at the cryptographic boundary.
SPR-13	The [spacecraft] encryption keys shall be restricted so that they cannot be read via any telecommands.{SV-AC-1,SV-AC-3}{AC-17(6),CM-3(6),SA-8(19),SA-9(6),SC-8(1),SC-12,SC-28(3)}	Telecommand paths are high-value targets for adversarial exploitation. Allowing keys to be retrieved via command interfaces creates a catastrophic failure mode. This constraint prevents exfiltration even under partial compromise of command processing logic. It ensures encryption protections cannot be remotely dismantled.
SPR-15	The [spacecraft] shall implement cryptographic mechanisms to identify and reject wireless transmissions that are deliberate attempts to achieve imitative or manipulative communications deception based on signal parameters.{SV-AV-1,SV-IT-1}{AC-3,AC-20,SA-8(19),SC-8(1),SC-23(3),SC-40(3),SI-4(13),SI-4(24),SI-4(25),SI-10(6)}	Adversaries may attempt imitative RF signals to inject commands or manipulate spacecraft behavior. Signal parameter validation (modulation, power, timing, waveform characteristics) strengthens command authentication beyond cryptographic validation alone. This helps mitigate spoofing, replay, and rogue emitter attacks. RF-layer validation complements cryptographic controls.
SPR-18	The [spacecraft] shall protect the confidentiality and integrity of information during preparation for transmission, transmission, and reception, in accordance with the [organization]‑provided encryption matrix.{SV-AC-7}{AC-3,SA-8(19),SC-8,SC-8(1),SC-8(2),SC-16,SC-16(1),SC-40}	* Preparation for transmission and during reception includes the aggregation, packing, and transformation options performed prior to transmission and the undoing of those operations that occur upon receipt.
SPR-19	The [spacecraft] shall encrypt all telemetry on downlink regardless of operating mode to protect current state of spacecraft.{SV-CF-4}{AC-3(10),RA-5(4),SA-8(18),SA-8(19),SC-8,SC-8(1),SC-13}	Telemetry exposes real-time spacecraft state and configuration. Unencrypted telemetry can reveal vulnerabilities, operational status, or targeting information. Enforcing encryption across all modes prevents intelligence collection and mission state inference. This mitigates passive RF interception threats.
SPR-26	The [spacecraft] shall use protected processing domains to enforce the policy that information does not leave the platform boundary unless it is encrypted as a basis for flow‑control decisions and shall enumerate permitted inter‑domain flows and enforce domain‑gate checks on any domain switch. {SV-AC-6}{AC-4(2),IA-9,SA-8(19),SC-8(1),SC-16(3)}	Domain gates provide controlled transition points between security domains. Enumerated flows prevent unintentional data leakage and enforce encryption policies at boundaries. This mitigates cross-domain injection and exfiltration. Strong gate enforcement prevents privilege escalation during context switching.
SPR-33	The [spacecraft] shall utilize TRANSEC. TRANSEC shall be implemented and verified as a distinct layer in coordination with Traffic Flow Security and RF anti‑fingerprinting.{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,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).
SPR-37	The [spacecraft] shall protect system components, associated data communications, and communication buses in accordance with: (i) national emissions and TEMPEST policies and procedures, and (ii) the security category or sensitivity of the transmitted information, and shall demonstrate compliance via pre‑launch TEMPEST‑like evaluation for co‑located payload configurations.{SV-CF-2,SV-MA-2}{PE-14,PE-19,PE-19(1),RA-5(4),SA-8(18),SA-8(19),SC-8(1)}	The measures taken to protect against compromising emanations must be in accordance with DODD S-5200.19, or superseding requirements. The concerns addressed by this control during operation are emanations leakage between multiple payloads within a single space platform, and between payloads and the bus.
SPR-44	The [spacecraft] shall maintain the confidentiality and integrity of information during preparation for transmission and during reception in accordance with [organization] provided encryption matrix.{SV-CF-1,SV-CF-2,SV-IT-2}{SA-8(19),SC-8,SC-8(1),SC-8(2),SC-8(3)}	* Preparation for transmission and during reception includes the aggregation, packing, and transformation options performed prior to transmission and the undoing of those operations that occur upon receipt.
SPR-45	The [spacecraft] shall implement cryptographic mechanisms that achieve protection against the effects of intentional electromagnetic interference; verification evidence for EMI/EPM shall be distinct from EMSEC/TEMPEST, anti‑jam/anti‑spoof protections, and EMP/HANE hardness.{SV-AV-1,SV-IT-1}{SA-8(19),SC-8(1),SC-40,SC-40(1)}	Intentional electromagnetic interference may attempt to induce predictable faults or bypass protections. Cryptographic resilience ensures corrupted transmissions are rejected. Verification must distinguish EMI/EPM resilience from TEMPEST and anti-jam protections. This ensures integrity under hostile RF environments.
SPR-47	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)}	Replay attacks can reuse valid command packets to manipulate spacecraft behavior. Freshness checks, nonces, and sequence enforcement prevent reuse of captured transmissions. Relay resistance mitigates man-in-the-middle exploitation. This protects command integrity over RF links.
SPR-48	The [spacecraft] shall implement cryptographic mechanisms to protect the integrity of audit information and audit tools.{SV-DCO-1}{AU-9(3),RA-10,SC-8(1),SI-3,SI-3(10),SI-4(24)}	Audit logs are essential for attribution and forensic analysis. If adversaries can modify audit data, detection and recovery become unreliable. Cryptographic integrity protections preserve evidentiary value.
SPR-49	The [spacecraft] shall implement cryptography for the indicated uses using the indicated protocols, algorithms, and mechanisms, in accordance with CNSSP 12 and applicable federal laws, Executive Orders, directives, policies, regulations, and standards.{IA-7,SC-8(1),SC-13,SI-12}
SPR-50	The [spacecraft] shall implement cryptographic mechanisms to protect the confidentiality and integrity of information during transmission unless otherwise protected by approved physical safeguards.{SV-AC-7}{SC-8,SC-8(1),SC-8(4),SI-7(6)}	Unprotected transmission exposes telemetry, commands, and state information to interception or manipulation. Cryptographic protections ensure authenticity and confidentiality across all communication paths. Physical safeguards alone are insufficient in contested environments.
SPR-51	The [spacecraft] shall implement cryptographic mechanisms to protect message externals unless otherwise protected by alternative physical safeguards.{SV-AC-7}{SC-8(3)}	Message externals (headers, routing data, metadata, protocol identifiers) can reveal operational state, enable traffic analysis, or be manipulated to redirect or replay communications. Cryptographic protection prevents adversaries from exploiting metadata to infer spacecraft posture or inject malicious traffic. Even if payload content is encrypted, unprotected externals can enable protocol exploitation or session hijacking. Physical safeguards alone are insufficient in contested RF environments.
SPR-148	The [spacecraft] shall protect the confidentiality and integrity of all transmitted information.{SV-IT-2,SV-AC-7}{SC-8}	* The intent as written is for all transmitted traffic to be protected. This includes internal to internal communications and especially outside of the boundary.
SPR-229	The [organization] shall protect documentation and Controlled Unclassified Information (CUI) as required, in accordance with the risk management strategy.{SV-CF-3,SV-SP-4,SV-SP-10}{AC-3,CM-12,CP-2,PM-17,RA-5(4),SA-3,SA-3(1),SA-5,SA-10,SC-8(1),SC-28(3),SI-12}	Documentation may reveal architecture details exploitable by adversaries. Proper handling prevents leakage. Protection of CUI supports regulatory compliance. Information governance complements technical controls.
SPR-230	The [organization] shall identify and properly classify mission sensitive design/operations information and access control shall be applied in accordance with classification guides and applicable federal laws, Executive Orders, directives, policies, regulations, and standards.{SV-CF-3,SV-AV-5}{AC-3,CM-12,CP-2,PM-17,RA-5(4),SA-3,SA-3(1),SA-5,SA-8(19),SC-8(1),SC-28(3),SI-12}	* Mission sensitive information should be classified as Controlled Unclassified Information (CUI) or formally known as Sensitive but Unclassified. Ideally these artifacts would be rated SECRET or higher and stored on classified networks. Mission sensitive information can typically include a wide range of candidate material: the functional and performance specifications, the RF ICDs, databases, scripts, simulation and rehearsal results/reports, descriptions of uplink protection including any disabling/bypass features, failure/anomaly resolution, and any other sensitive information related to architecture, software, and flight/ground /mission operations. This could all need protection at the appropriate level (e.g., unclassified, SBU, classified, etc.) to mitigate levels of cyber intrusions that may be conducted against the project’s networks. Stand-alone systems and/or separate database encryption may be needed with controlled access and on-going Configuration Management to ensure changes in command procedures and critical database areas are tracked, controlled, and fully tested to avoid loss of science or the entire mission.
SPR-244	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.{SV-AC-7,SV-CF-1}{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}	Standardized secure protocols reduce interoperability risk. Alignment with federal standards ensures validated cryptography. Defined protocols prevent ad hoc insecure implementations. Governance strengthens communication assurance.
SPR-457	The [spacecraft] shall verify cryptographic integrity and origin of data at each relay hop before forwarding information between internal components, payloads, crosslinks, and ground.{SV-IT-1,SV-IT-2,SV-AC-3}{CA-3(7),SC-8(1),SC-13,SC-23}	End-to-end security alone is insufficient in multi-hop spacecraft architectures. Verifying integrity and origin at each relay prevents compromised subsystems from forwarding malicious data laterally. Hop-by-hop validation limits propagation of injected commands or payload tampering. This enforces zero-trust principles internally.
SPR-491	The [spacecraft] shall employ transmission security techniques that conceal or randomize RF signal parameters, including modulation, timing, and power characteristics, to prevent signal fingerprinting and association in accordance with the System TRANSEC Plan. Implementation and verification shall be coordinated with TRANSEC and Traffic Flow Security.{SV-CF-2}{SC-8,SC-40(4)}	Concealing RF characteristics prevents signal fingerprinting. Randomization reduces tracking and targeting risk. Coordinated TRANSEC alignment strengthens defense. Signal agility enhances survivability.
SPR-492	The [spacecraft] shall update signal parameter selections using cryptographically sound PRNG inputs at [organization]‑defined intervals or triggers, coordinated with TRANSEC and Traffic Flow Security.{SV-CF-2,SV-AC-3}{SC-8,SC-12,SC-40(4)}	Predictable signal patterns enable adversary exploitation. Strong PRNG inputs ensure randomness integrity. Coordinated update intervals prevent synchronization attacks. Cryptographic randomness strengthens concealment.
SPR-543	The [spacecraft] shall complement link‑layer protections with per‑message MACs/signatures for commands and selected telemetry so integrity and origin assurance persist across relays and storage/forwarding; operator feedback shall distinguish corruption vs. integrity vs. authentication failures.{SV-IT-1,SV-AC-2}{AC-17(10),SC-8,SC-8(2)}	Storage/forwarding relays can break link-layer trust. Message-level MACs preserve end-to-end assurance. Clear error distinctions aid operators. Layered integrity strengthens trust continuity.