Replay of recorded authentic communications traffic at a later time with the hope that the authorized communications will provide data or some other system reaction
| SPARTA ID | Requirement | Rationale/Additional Guidance/Notes |
|---|---|---|
| SPR-14 | The [spacecraft] shall authenticate the ground station (and all commands) and other spacecraft before establishing remote connections using bidirectional authentication that is cryptographically based.{SV-AC-1,SV-AC-2}{AC-3,AC-17,AC-17(2),AC-17(10),AC-18(1),AC-20,IA-3(1),IA-4,IA-4(9),IA-7,IA-9,SA-8(18),SA-8(19),SA-9(2),SC-7(11),SC-16(1),SC-16(2),SC-16(3),SC-23(3),SI-3(9)} | Authorization can include embedding opcodes in command strings, using trusted authentication protocols, identifying proper link characteristics such as emitter location, expected range of receive power, expected modulation, data rates, communication protocols, beamwidth, etc.; and tracking command counter increments against expected values. |
| SPR-31 | The [spacecraft] shall fail securely to a secondary device in the event of an operational failure of a primary boundary protection device (i.e., crypto solution).{SV-AC-1,SV-AC-2,SV-CF-1,SV-CF-2}{CP-13,SA-8(19),SA-8(24),SC-7(18),SI-13,SI-13(4)} | If a primary boundary protection device fails, the spacecraft must not revert to insecure operation. Secure failover ensures continuity of confidentiality and integrity protections. This prevents adversaries from inducing failure states to bypass encryption. Redundancy strengthens mission resilience. |
| SPR-46 | The [spacecraft] shall monitor [Program‑defined telemetry points] for malicious commanding attempts and alert ground operators upon detection.{SV-AC-2,SV-IT-1,SV-DCO-1}{AC-17,AC-17(1),AC-17(10),AU-3(1),RA-10,SC-7,SC-16,SC-16(2),SC-16(3),SI-3(8),SI-4,SI-4(1),SI-4(13),SI-4(24),SI-4(25),SI-10(6)} | Telemetry-based detection enables identification of anomalous command patterns, replay attempts, and injection attacks. Early detection allows rapid containment before mission impact escalates. Onboard monitoring is critical when ground latency limits intervention. This supports proactive defense. |
| 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-68 | The [spacecraft] shall have on-board intrusion detection/prevention system that monitors the mission critical components or systems.{SV-AC-1,SV-AC-2,SV-MA-4}{RA-10,SC-7,SI-3,SI-3(8),SI-4,SI-4(1),SI-4(7),SI-4(13),SI-4(24),SI-4(25),SI-10(6)} | The mission critical components or systems could be GNC/Attitude Control, C&DH, TT&C, Fault Management. |
| SPR-96 | The [spacecraft] shall uniquely identify and authenticate the ground station and other spacecraft before establishing a remote connection.{SV-AC-1,SV-AC-2}{AC-3,AC-17,AC-17(10),AC-20,IA-3,IA-4,SA-8(18),SI-3(9)} | |
| SPR-97 | All [spacecraft] commands which have unrecoverable consequence must have dual authentication prior to command execution. The [spacecraft] shall verify two independent cryptographic approvals prior to execution and shall generate an audit record binding both approver identifiers to the command identifier, time, and outcome.{SV-AC-4,SV-AC-8,SV-AC-2}{AU-9(5),IA-3,IA-4,IA-10,PE-3,PM-12,SA-8(15),SA-8(21),SC-16(2),SC-16(3),SI-3(8),SI-3(9),SI-4(13),SI-4(25),SI-7(12),SI-10(6),SI-13} | Commands with irreversible impact require heightened assurance to prevent catastrophic mission loss. Dual independent cryptographic approvals mitigate insider threat, key compromise, and single-point credential abuse. Binding approver identifiers to the audit trail strengthens accountability and deterrence. This reduces the probability of unauthorized hazardous command execution. |
| SPR-98 | The [spacecraft] shall have a method to ensure the integrity of which have unrecoverable consequence and validate their authenticity before execution.{SV-AC-2,SV-IT-2,SV-IT-1}{AU-9(5),IA-3,IA-4,IA-10,PE-3,PM-12,SA-8(15),SA-8(21),SC-16(2),SC-16(3),SI-3(8),SI-3(9),SI-4(13),SI-4(25),SI-7(12),SI-10(6),SI-13} | Hazardous commands must be cryptographically protected and validated prior to execution. Integrity and authenticity checks prevent replay, modification, or injection of destructive instructions. Without validation, RF interception or command path compromise could result in mission-ending actions. This ensures critical commands are both authorized and unaltered. |
| SPR-100 | The [spacecraft] shall monitor [Program defined telemetry points] for malicious commanding attempts.{SV-AC-1,SV-AC-2}{SC-7,AU-3(1),AC-17(1)} | Source from AEROSPACE REPORT NO. TOR-2019-02178 Vehicle Command Counter (VCC) - Counts received valid commands Rejected Command Counter - Counts received invalid commands Command Receiver On/Off Mode - Indicates times command receiver is accepting commands Command Receivers Received Signal Strength - Analog measure of the amount of received RF energy at the receive frequency Command Receiver Lock Modes - Indicates when command receiver has achieved lock on command signal Telemetry Downlink Modes - Indicates when the satellite’s telemetry was transmitting Cryptographic Modes - Indicates the operating modes of the various encrypted links Received Commands - Log of all commands received and executed by the satellite System Clock - Master onboard clock GPS Ephemeris - Indicates satellite location derived from GPS Signals |
| SPR-119 | The [spacecraft] shall implement cryptography for the indicated uses using the indicated protocols, algorithms, and mechanisms, in accordance with applicable federal laws, Executive Orders, directives, policies, regulations, and standards: [NSA- certified or approved cryptography for protection of classified information, FIPS-validated cryptography for the provision of hashing].{SV-AC-1,SV-AC-2,SV-CF-1,SV-CF-2,SV-AC-3}{IA-7,SC-13} | Use of NSA-certified or FIPS-validated cryptography ensures compliance with federal mandates and high-assurance algorithms. Standardized implementations reduce algorithmic weaknesses. Alignment with policy ensures interoperability and trustworthiness. Proper certification mitigates cryptographic implementation flaws. |
| SPR-129 | The [spacecraft] shall restrict the use of information inputs to spacecraft and designated ground stations as defined in the applicable ICDs.{SV-AC-1,SV-AC-2}{AC-20,SC-23,SI-10,SI-10(5),SI-10(6)} | Limiting inputs to approved spacecraft and ground stations reduces spoofing and injection risk. ICD-defined boundaries prevent rogue sources from influencing control systems. This constrains trust relationships. Controlled input surfaces reduce attack vectors. |
| SPR-131 | The [spacecraft] shall identify and reject commands received out-of-sequence when the out-of-sequence commands can cause a hazard/failure or degrade the control of a hazard or mission.{SV-AC-2,SV-AV-4}{SC-16(2),SI-4(13),SI-4(25),SI-10,SI-10(6),SI-13} | Command sequencing enforces operational logic and safety interlocks. Out-of-sequence commands may bypass safeguards. Sequence enforcement prevents replay and control manipulation. This preserves control flow integrity. |
| SPR-157 | The [spacecraft] shall explicitly indicate when a communication session has been terminated.{SV-AC-2,SV-IT-1}{AC-12(2)} | Clear indication of session termination prevents ambiguity in communication state. This reduces session hijacking risk. Operators must know when secure state has ended. Transparency strengthens trust. |
| SPR-158 | The [spacecraft] shall provide a user-initiated (i.e., ground terminal) logout capability for communications sessions.{SV-AC-2,SV-IT-1}{AC-12(1)} | Manual logout supports explicit session control. This prevents lingering authenticated sessions. User agency reduces misuse risk. Proper session closure mitigates replay attacks. |
| SPR-201 | The [spacecraft] shall monitor all inbound/outbound communications to detect unusual or unauthorized behavior and respond appropriately (disregard command, deny connection, etc.){SV-IT-1,SV-AC-2,SV-IT-2,SV-CF-1}{SI-4(4)} | Continuous traffic inspection detects unauthorized behavior. Both inbound and outbound flows may signal compromise. Real-time response reduces dwell time. Visibility across communication paths is essential in contested environments. |
| SPR-519 | The [spacecraft] shall cryptographically bind audit records to their origin using per‑record MACs/signatures or sequence‑linked hashes and include station/operator ID and selected RF/link indicators (e.g., SNR/BER, frame counters) when available; ground shall verify and log the results.{SV-IT-2,SV-AC-2,SV-DCO-1}{AU-3,AU-3(1),AU-9,AU-9(2),AU-10} | Per-record signatures prevent tampering or replay. Sequence linkage detects gaps. Including RF indicators enhances forensic value. Verified logging strengthens evidentiary integrity. |
| SPR-522 | The [organization] shall implement a canonical time base and identifiers (station ID, session ID, command ID/APID, image/bitstream IDs) across TT&C front ends, consoles, and on‑board logs and shall de‑duplicate and gap‑detect during aggregation with rules for the source of truth for command history.{SV-IT-1,SV-AC-2,SV-DCO-1}{AU-6,AU-6(4),AU-8,IA-4} | Unified identifiers prevent ambiguity in command history. Gap detection identifies dropped or spoofed entries. Clear source-of-truth logic prevents dispute. Time discipline strengthens forensic precision. |
| SPR-532 | The [spacecraft] shall authenticate inter‑service exchanges (e.g., planning > command stacks, payload summaries > bus) using message‑level MACs/signatures or mutually authenticated channels appropriate to resource limits, and shall verify provenance for code‑driven actions.{SV-IT-1,SV-AC-2}{IA-9,AC-4} | Internal services must not assume implicit trust. Message-level authentication prevents spoofing. Resource-appropriate methods balance cost and assurance. Provenance verification strengthens command chain integrity. |
| 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. |
| SPR-544 | The [spacecraft] shall close sessions at LOS, invalidate per‑session tokens/nonces, and safely pause queued procedures with no partial side effects, supporting resumable execution at next AOS with explicit telemetry of residual stacks and state.{SV-AC-2}{AC-12,SC-10,IA-5} | Session invalidation prevents replay or token reuse. Safe pausing prevents partial side effects. Resumable logic supports orbital realities. Session discipline strengthens security. |
| ID | Name | Description | |
|---|---|---|---|
| IA-0008 | Rogue External Entity | Adversaries obtain a foothold by interacting with the spacecraft from platforms outside the authorized ground architecture. A “rogue external entity” is any actor-controlled transmitter, platform, or node, ground, maritime, airborne, or space-based. Most interact by radiating or exchanging traffic using mission-compatible waveforms, framing, or crosslink protocols. Others carry no mission-compatible capability at all, and instead apply interference, directed energy, or physical proximity to shape the conditions under which access becomes possible. The technique exploits the fact that many vehicles must remain commandable and discoverable over wide areas and across multiple modalities. Using public ephemerides, pass predictions, and knowledge of acquisition procedures, the actor times transmissions to line-of-sight windows, handovers, or maintenance periods. Initial access stems from presenting traffic that the spacecraft will parse or prioritize, such as syntactically valid telecommands, crafted ranging/acquisition exchanges, crosslink service advertisements, or payload/user-channel messages that bridge into the command/data path, or, for entities operating by effect rather than by protocol, from the contingency behavior those effects induce. | |
| IA-0008.01 | Rogue Ground Station | Adversaries may field their own ground system, transportable or fixed, to transmit and receive mission-compatible signals. A typical setup couples steerable apertures and GPS-disciplined timing with SDR/modems configured for the target’s bands, modulation/coding, framing, and beacon structure. Using pass schedules and Doppler/polarization predictions, the actor crafts over-the-air traffic that appears valid at the RF and protocol layers. | |
| EX-0001 | Replay | Replay is the re-transmission of previously captured traffic, over RF links, crosslinks, or internal buses, to elicit the same processing and effects a second time. Adversaries first observe and record authentic exchanges (telecommands, ranging/acquisition frames, housekeeping telemetry acknowledgments, bus messages), then resend them within acceptance conditions that the system recognizes, matching link geometry, timetags, counters, or mode states. The aim can be functional (re-triggering an action such as a mode change), observational (fingerprinting how the vehicle reacts at different states), or disruptive (saturating queues and bandwidth to crowd out legitimate traffic). Because replays preserve valid syntax and often valid context, they can blend with normal operations, especially during periods with reduced monitoring or when counters and windows reset (e.g., handovers, safing entries). On encrypted links, metadata replays (acquisition beacons, schedule requests) may still yield informative responses. | |
| EX-0001.01 | Command Packets | Threat actors may resend authentic-looking telecommands that were previously accepted by the spacecraft. Captures may include whole command PDUs with framing, CRC/MAC, counters, and timetags intact, or they may be reconstructed from operator tooling and procedure logs. When timing, counters, and mode preconditions align, the replayed packet can cause the same effect: toggling relays, initiating safing or recovery scripts, adjusting tables, commanding momentum dumps, or scheduling delta-v events. Even when outright execution fails, repeated “near-miss” injections can map acceptance windows, rate/size limits, and interlocks by observing the spacecraft’s acknowledgments and state changes. At scale, streams of valid-but-stale commands can congest command queues, delay legitimate activity, or trigger nuisance FDIR responses. | |
| EX-0001.02 | Bus Traffic Replay | Instead of the RF path, the attacker targets internal command/data handling by injecting or retransmitting messages on the spacecraft bus (e.g., 1553, SpaceWire, custom). Because many subsystems act on the latest message or on message rate rather than on uniqueness, a flood of historical yet well-formed frames can consume bandwidth, starve critical publishers, or cause subsystems to perform the same action repeatedly. Secondary effects include stale sensor values being re-consumed, watchdog timers being reset at incorrect intervals, and autonomy rules misclassifying the situation due to out-of-order but valid-looking events. On time-triggered or scheduled buses, replaying at precise offsets can collide with or supersede legitimate messages, steering system state without changing software. The goal is to harness the bus’s determinism, repeating prior internal stimuli to recreate prior effects or to induce resource exhaustion. | |
| EXF-0001 | Replay | The adversary re-sends previously valid commands or procedures to cause the spacecraft to transmit data again, then captures the resulting downlink. Typical targets are recorder playbacks, payload product dumps, housekeeping snapshots, or file directory listings. By aligning replays with geometry (e.g., when the satellite is in view of actor-controlled apertures) and with acceptance conditions (counters, timetags, mode), the attacker induces legitimate transmissions that appear routine to operators. Variants include selectively replaying index ranges to fetch only high-value intervals, reissuing subscription/telemetry-rate changes to increase data volume, or queueing playbacks that fire during later passes when interception is feasible. | |
| IMP-0001 | [DEPRECATED] Deception (or Misdirection) | Measures designed to mislead an adversary by manipulation, distortion, or falsification of evidence or information into a system to induce the adversary to react in a manner prejudicial to their interests. Threat actors may seek to deceive mission stakeholders (or even military decision makers) for a multitude of reasons. Telemetry values could be modified, attacks could be designed to intentionally mimic another threat actor's TTPs, and even allied ground infrastructure could be compromised and used as the source of communications to the spacecraft. | |
| ID | Name | Description | NIST Rev5 | D3FEND | ISO 27001 | |
|---|---|---|---|---|---|---|
| CM0077 | Space Domain Awareness | Space domain awareness (SDA) enables mission owners to detect and characterize objects, behaviors, environmental conditions, and anomalous events that may affect their space systems. When correlated with other intelligence and mission data, SDA can also support assessment of possible threats and attribution. SDA encompasses the tracking and cataloging of space objects, prediction of future object positions, monitoring of the space environment and space weather, and characterization of the capabilities and behaviors of on-orbit objects. SDA data must provide the accuracy, timeliness, coverage, and characterization needed for the mission’s defined decisions. Publicly available data may support general awareness but may be insufficient for time-sensitive conjunction, proximity, or threat assessment; appropriate government, commercial, partner, or owner-operator data should be obtained where required. SDA is generated by a diverse sensor architecture spanning terrestrial optical, infrared, and radar systems and space-based sensors including inspector satellites capable of close-approach observation. The SDA landscape is increasingly populated by national space agencies, military programs, allied partners, commercial providers, and amateur tracking communities, making the space environment progressively more transparent and creating opportunities for mission owners to leverage diverse data sources to build a more complete operational picture. | CP-13 CP-2(3) CP-2(5) CP-2(7) PE-20 PE-6 PE-6(1) PE-6(2) PE-6(4) RA-6 SI-4(17) | D3-APLM D3-PM D3-HCI D3-SYSM | A.5.29 A.7.4 A.8.16 A.7.4 A.7.4 A.5.10 | |
| CM0078 | Space-Based Radio Frequency Mapping | Space-based radio frequency (RF) mapping can provide broad-area monitoring and analysis of RF activity affecting space systems in orbit and on the ground. Depending on the sensor architecture, it may support recurring or persistent detection, signal characterization, and geolocation of interference sources, with performance determined by factors such as frequency coverage, signal strength, antenna pattern, sensor geometry, and revisit rate. By correlating RF observations with mission link performance, operators can better distinguish potential jamming or spoofing from unintentional interference and estimate relevant signal characteristics and source location. Although these observations do not independently establish intent, attribution, or a precise emitter location in every case, they provide an important intelligence layer that supports faster investigation and more informed defensive decisions when communications degradation occurs. | PE-20 RA-6 SI-4(14) | D3-APLM D3-DEM D3-SVCDM D3-SYSM | A.5.10 | |
| CM0081 | Defensive Jamming and Spoofing | Defensive jamming and spoofing are active electronic countermeasures that may disrupt or deceive the terminal guidance sensors of an incoming kinetic anti-satellite weapon. When combined with evasive maneuvering, these measures may reduce the accuracy of the threat’s targeting solution and lower the probability of a successful intercept. Effectiveness depends on timely threat detection, knowledge of the relevant sensor characteristics, available transmit power and geometry, and the threat’s ability to recognize or overcome the countermeasure. Development, testing, and employment of these capabilities must occur only under applicable governmental authorization, spectrum authority, rules of engagement, and information-protection requirements. The design must limit unintended interference and account for effects on friendly, civil, and safety-related radio services. | CP-10(6) CP-13 CP-2 CP-2(1) CP-2(5) CP-2(7) PE-20 | D3-DO | 7.5.1 7.5.2 7.5.3 A.5.2 A.5.29 A.8.1 A.5.30 A.5.29 A.5.10 | |
| CM0083 | Antenna Nulling and Adaptive Filtering | Antenna nulling and adaptive filtering are complementary electronic protection techniques that reduce the effects of jamming on spacecraft communication and sensing links while preserving access to legitimate signals. Antenna nulling dynamically adjusts the receive antenna pattern to reduce sensitivity in the estimated direction of arrival of a jammer. For terrestrial interference, the affected geographic region depends on the spacecraft’s position and attitude, antenna geometry, and uncertainty in the jammer’s location. Nulling is most effective against a limited number of discrete, detectable interference sources, but it may also attenuate legitimate signals arriving from the same or a nearby direction. Adaptive filtering suppresses interference based on its spectral or signal characteristics, such as by placing adaptive notches around narrowband or slowly varying interference. It can preserve operation within unaffected portions of the received bandwidth but may also remove or distort legitimate signal energy that overlaps the rejected frequencies. Its effectiveness decreases against wideband, rapidly changing, or multiple simultaneous jammers when too little usable bandwidth remains to support mission requirements. Used together, antenna nulling and adaptive filtering can address a broader range of jamming conditions than either technique alone. Both techniques depend on the interference remaining within the operating range of the antenna and receiver chain. If a jammer saturates or damages the low-noise amplifier, analog front end, or analog-to-digital converter, downstream digital processing may be unable to recover the legitimate signal. Receiver dynamic range and front-end protection must therefore be incorporated into the overall electronic protection design. | SC-40 SI-4(14) | D3-PH | None | |
| CM0002 | COMSEC | Communications security (COMSEC) denies unauthorized parties access to information derived from telecommunications while ensuring the authenticity of those communications. COMSEC is commonly defined as a broad discipline that may encompass cryptographic security, transmission security, emissions security, cryptographic key management, traffic-flow security, and physical security of COMSEC material. Within SPARTA, these areas are further broken down through separate countermeasures, including CM0029 | TRANSEC, CM0030 | Crypto Key Management, CM0003 | TEMPEST/EMSEC, and CM0073 | Traffic Flow Analysis Defense. CM0002 provides the overarching communications-security context and supports the coordinated application of these specialized countermeasures. All mission links, particularly telemetry, tracking, and commanding (TT&C) links, should employ communications-security protections appropriate to the sensitivity, criticality, operational environment, and threat exposure of the information being exchanged. These protections may include cryptographic protection, transmission security, emissions security, traffic-flow protection, secure key management, and physical protection of COMSEC material, as addressed by the applicable specialized countermeasures. Spacecraft should not provide an operational mode that permits required cryptographic protection or command authentication on TT&C links to be bypassed or disabled. Operational, maintenance, test, recovery, and contingency modes should be considered when evaluating whether communications-security protections can be unintentionally or improperly circumvented. Communication receivers and associated signal-processing or TRANSEC mechanisms should detect and, when mission-defined criteria are met, reject or otherwise safely handle transmissions exhibiting anomalous signal characteristics consistent with communications deception. Cryptographic mechanisms should authenticate and integrity-check received content but should not be treated as RF-deception detectors. | AC-17 AC-17(1) AC-17(10) AC-17(2) AC-18 AC-18(1) AC-2(11) AC-3(10) CA-3 IA-4(9) IA-5 IA-5(7) IA-7 PL-8 PL-8(1) SA-8(18) SA-8(19) SA-9(6) SC-10 SC-12 SC-12(1) SC-12(2) SC-12(3) SC-12(6) SC-13 SC-16(3) SC-28(1) SC-28(3) SC-7 SC-7(10) SC-7(11) SC-7(18) SC-7(5) SC-8(1) SC-8(3) SI-10 SI-10(3) SI-10(5) SI-10(6) SI-19(4) SI-3(8) | D3-ET D3-MH D3-MAN D3-MENCR D3-NTF D3-ITF D3-OTF D3-CH D3-DTP D3-NTA D3-CAA D3-DNSTA D3-IPCTA D3-NTCD D3-RTSD D3-PHDURA D3-PMAD D3-CSPP D3-MA D3-SMRA D3-SRA | A.5.14 A.6.7 A.8.1 A.8.16 A.5.14 A.8.1 A.8.20 A.5.14 A.8.21 A.5.16 A.5.17 A.5.8 A.5.14 A.8.16 A.8.20 A.8.22 A.8.23 A.8.26 A.8.12 A.5.33 A.8.20 A.8.24 A.8.24 A.8.26 A.5.31 A.5.33 A.8.11 | |
| CM0030 | Crypto Key Management | Effective cryptographic key management is a foundational requirement for all mission encryption and authentication functions; the security of cryptographic implementations is only as strong as the protection afforded to the keys those implementations rely upon. Key management must conform to recognized cryptographic guidance and address the full lifecycle applicable to each key type, including generation or establishment, distribution, storage, activation, use, replacement, deactivation or revocation, recovery where authorized, compromise response, and destruction. Only approved cryptographic algorithms, key generation methods, key distribution techniques, and authentication mechanisms may be used; the use of unapproved, deprecated, or custom cryptographic primitives is prohibited regardless of perceived functional adequacy. Encryption key handling must be performed outside of onboard software and protected through dedicated cryptographic mechanisms, preventing keys from being exposed through software vulnerabilities, memory inspection, or software-level debugging interfaces. Secret and private key material must not be retrievable in plaintext through telecommands, telemetry, diagnostic outputs, debugging interfaces, or other externally accessible mechanisms, regardless of the privilege level of the requesting entity. | CM-3(6) PL-8 PL-8(1) SA-3 SA-4(5) SA-8 SA-9(6) SC-12 SC-12(1) SC-12(2) SC-12(3) SC-12(6) SC-28(3) SC-8(1) | D3-CH D3-CP | A.5.8 A.5.2 A.5.8 A.8.25 A.8.31 A.8.27 A.8.28 A.5.33 A.8.24 | |
| CM0031 | Authentication | All command-bearing sessions, frames, or messages involving spacecraft command links, crosslinks, or relay services shall provide cryptographic authentication of the command origin and integrity verification before commands are accepted. Mutual or bidirectional authentication shall be required where both endpoints must authenticate one another and the link and protocol architecture support that exchange. Acquisition requirements should mandate cryptographically based, bidirectional authentication for all command sessions across external links, including ground-to-spacecraft uplinks, spacecraft-to-spacecraft crosslinks, and any relay or intermediary ground station connections, with authentication required aBidirectional authentication enables both communicating entities to verify each other’s identity and helps prevent impersonation. Authentication establishes identity but does not by itself authorize a command, protect mission-data confidentiality, or prevent session hijacking. Command acceptance must also enforce authorization, and authenticated sessions or security associations must maintain integrity and replay resistance so that subsequent traffic remains bound to the authenticated entities. Beyond external links, authentication is strongly recommended for spacecraft internal bus communications and onboard inter-component connections, as an adversary with access to internal interfaces, whether through a compromised component or a physical access event, should face the same authentication barrier as an external adversary attempting to inject commands from outside the spacecraft. | AC-14 AC-17 AC-17(10) AC-17(2) AC-18 AC-18(1) IA-2 IA-3(1) IA-4 IA-4(9) IA-7 IA-9 PL-8 PL-8(1) SA-3 SA-4(5) SA-8 SA-8(15) SA-8(9) SC-16 SC-16(1) SC-16(2) SC-32(1) SC-7(11) SC-8(1) SI-14(3) SI-7(6) | D3-MH D3-MAN D3-CH D3-BAN D3-MFA D3-TAAN D3-CBAN | A.5.14 A.6.7 A.8.1 A.5.14 A.8.1 A.8.20 A.5.16 A.5.16 A.5.8 A.5.2 A.5.8 A.8.25 A.8.31 A.8.27 A.8.28 A.5.33 | |
| CM0033 | Relay Protection | Replay attacks capture and later retransmit previously valid authentication messages, frames, credentials, or tokens. Relay attacks forward an authentication exchange in real time between legitimate endpoints, causing an endpoint to authenticate a connection or action that the adversary is relaying without requiring compromise of the underlying cryptographic keys. Relay- and replay-resistant authentication mechanisms must be implemented when establishing remote connections or security associations with the spacecraft and for authenticated communications on spacecraft internal buses. The protections must prevent previously accepted authentication material or authenticated traffic from being reused outside its authorized context. Replay resistance should use freshness and anti-reuse mechanisms such as nonces, sequence numbers, timestamps where operationally suitable, and managed anti-replay windows. Relay resistance additionally requires authentication to be cryptographically bound to the intended endpoints, security association, session or channel context, and authenticated action. Challenge-response authentication provides replay resistance when fresh challenges are used but does not, by itself, prevent an adversary from relaying the challenge and response between legitimate endpoints. These protections must be applied at both external interface boundaries, including ground-to-spacecraft command links and crosslinks, and internal spacecraft bus connections where component-to-component authentication is implemented. | AC-17(10) IA-2(8) IA-3 IA-3(1) IA-4 IA-7 SC-13 SC-16(1) SC-23 SC-23(1) SC-23(3) SC-7 SC-7(11) SC-7(18) SI-10 SI-10(5) SI-10(6) SI-3(8) | D3-ITF D3-NTA D3-OTF | A.5.16 A.5.14 A.8.16 A.8.20 A.8.22 A.8.23 A.8.26 A.8.24 A.8.26 A.5.31 | |
| CM0036 | Session Termination | Where session-oriented communications are used between ground systems and spacecraft, between ground system components, or across internal spacecraft interfaces, the associated connection or session must be terminated upon completion or after a period of inactivity exceeding a threshold defined in the mission’s concept of operations (CONOPS). Failure to terminate idle or completed sessions leaves authenticated connections open and exploitable, providing adversaries with an opportunity to inject commands or data into an existing authenticated session without needing to complete the authentication process independently. Inactivity timeout thresholds must be established through the CONOPS process rather than set arbitrarily, balancing the security benefit of rapid session termination against the operational consequences of terminating a session that an operator or automated process may legitimately require across a contact gap or processing delay. Session termination must invalidate the associated session identifiers, authorization state, and cryptographic session state so that the terminated session cannot be reused. Where secure session resumption is operationally required, it must use a mission-approved, cryptographically protected mechanism with defined validity limits and must not permit reuse of expired, revoked, or invalidated session state. | AC-12 AC-12(2) SC-10 SI-14(3) SI-4(7) | D3-SDA | A.8.20 | |
| CM0055 | Secure Command Mode(s) | Secure command modes provide additional layers of restriction on spacecraft command acceptance beyond standard authentication and encryption, constraining when, where, and under what operational conditions the spacecraft will process commands. These supplemental controls reduce the window of opportunity for unauthorized commanding by limiting command receptivity to defined parameters that an adversary would need to satisfy simultaneously with authentication requirements, substantially increasing the difficulty of a successful command injection attack. Specific implementations include geographic restriction, in which the spacecraft accepts commands only when in contact with designated ground station locations; operational mode restrictions, in which special flight software (FSW) modes must be active before certain command categories are accepted; and temporal controls, in which the spacecraft enforces time-bounded windows during which commands are valid. These mechanisms complement command authentication, integrity protection, anti-replay controls, and authorization and do not replace them. Encryption should also be applied where command confidentiality is required. Secure command modes may combine geographic, temporal, operational-state, source, or other mission-defined conditions according to the active command policy. Secure command modes helps create a multi-dimensional command acceptance policy that an adversary must defeat in its entirety to achieve unauthorized command execution. | AC-17(1) AC-17(10) AC-2(11) AC-2(12) AC-3 AC-3(2) AC-3(3) AC-3(4) AC-3(8) CA-3(7) IA-10 PL-8 PL-8(1) SA-3 SA-8 SC-7 SI-3(8) | D3-AH D3-ACH D3-MFA D3-OTP | A.8.16 A.5.15 A.5.33 A.8.3 A.8.4 A.8.18 A.8.20 A.8.2 A.8.16 A.5.8 A.5.2 A.5.8 A.8.25 A.8.31 A.8.27 A.8.28 A.5.14 A.8.16 A.8.20 A.8.22 A.8.23 A.8.26 | |
| CM0034 | Monitor Critical Telemetry Points | Monitoring defined spacecraft telemetry points provides a key source of evidence for detecting adversary activity against on-orbit systems, where observability is largely limited to the events and conditions the spacecraft can sense, record, and report. Monitored telemetry must include both accepted and rejected commands, command mode transitions, command counters, and other indicators of commanding activity, enabling detection of unauthorized command attempts that fail authentication as well as anomalous patterns in legitimate command traffic. Monitoring scope should include RF and link-quality indicators that support detection and triage of interference or suspected jamming. These indicators should be correlated with expected link conditions and other available evidence before hostile activity is concluded. Security-relevant telemetry should be integrated and time-correlated with ground-based defensive cyber operations infrastructure, including security information and event management (SIEM) and audit platforms, to provide unified space-system cybersecurity situational awareness. The resulting view should correlate spacecraft observations with relevant ground-system security events while accounting for telemetry latency, contact availability, and other observability limitations. | AC-17(1) AU-3(1) CA-7(6) IR-4(14) PL-8 PL-8(1) SA-8(13) SC-16 SC-16(1) SC-7 SI-3(8) SI-4(7) | D3-NTA D3-PM D3-PMAD D3-RTSD | A.8.16 A.5.8 A.5.14 A.8.16 A.8.20 A.8.22 A.8.23 A.8.26 | |
| CM0029 | TRANSEC | Transmission security (TRANSEC) is the component of communications security (COMSEC) concerned with protecting the characteristics of the transmission itself, as distinct from protecting the content of the information being communicated. TRANSEC controls reduce the likelihood, effectiveness, or operational impact of transmission interception, signal disruption, communications deception, and exploitation of transmission characteristics within the defined threat model. Applicable TRANSEC techniques include jam-resistant waveforms that increase resistance to jamming and communications deception, spread spectrum and frequency hopping techniques that reduce signal predictability and improve resistance to interception and disruption, low probability of intercept and low probability of detection (LPI/LPD) signal designs that reduce transmission observability, and transmission scheduling or pattern discipline that limits the intelligence value of traffic analysis. TRANSEC requirements should be applied to mission communication links according to link criticality (e.g., TT&C, crosslinks), threat exposure, and operational consequence. TRANSEC must be treated as a distinct layer of protection complementary to, but not a substitute for, cryptographic protection of information content. | AC-17 AC-18 AC-18(5) CA-3 CP-8 PL-8 PL-8(1) SA-8(19) SC-16 SC-16(1) SC-40 SC-40(1) SC-40(3) SC-40(4) SC-5 SC-8(1) SC-8(3) SC-8(4) | 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 | A.5.14 A.6.7 A.8.1 A.5.14 A.8.1 A.8.20 A.5.14 A.8.21 A.5.29 A.7.11 A.5.8 A.5.33 | |