The adversary alters how the spacecraft validates authority so that future inputs are accepted on their terms. Modifications can target code (patching flight binaries, hot-patching functions in memory, hooking command handlers), data (changing key identifiers, policy tables, or counter initialization), or control flow (short-circuiting MAC checks, widening anti-replay windows, bypassing interlocks on specific opcodes). Common choke points include telecommand verification routines, bootloader or update verifiers, gateway processors that bridge payload and bus traffic, and maintenance dictionaries invoked in special modes. Subtle variants preserve outward behavior, producing normal-looking acknowledgments and counters, while internally accepting a broader set of origins, opcodes, or timetags. Others introduce conditional logic so the backdoor only activates under specific geometry or timing, masking during routine audit. Once resident, the modified process becomes the new trust oracle, enabling recurring execution for the attacker and, in some cases, denying legitimate control by causing authentic inputs to fail verification or to be deprioritized.
| ID | Name | Tiering | Description | NIST Rev5 | ISO 27001 | Onboard SV | Ground | |
| 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) | 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) | 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 | ||||
| CM0021 | Software Digital Signature | Each software or firmware image subject to installation or update control shall be verified using an approved digital signature and an approved trust anchor before installation or activation. The trust anchor may be represented by a certificate or by a directly provisioned verification key, depending on the approved trust architecture. Successful verification establishes that the image was signed by an authorized signing identity and has not been modified since signing; it does not establish that the signed code is non-malicious, vulnerability-free, or operationally safe. Signature verification confirms the integrity and approved origin of the software but does not, by itself, prevent installation of an older validly signed version; update authorization and rollback protections must be enforced separately. The verification mechanism must be implemented such that it cannot be bypassed through operational commands, configuration changes, or software updates, and must reject any component whose signature is absent or invalid, or whose signing certificate or trust anchor is not recognized and approved by the mission. Digital signature enforcement complements but is distinct from the boot-time chain of trust established through secure boot; it applies to software installation and update events throughout the operational lifecycle, not only at system startup. | AC-14 CM-11 CM-11(3) CM-14 CM-5(6) IA-2 SA-10(1) SA-11 SA-4(5) SA-8(29) SA-8(31) SA-9 SI-7 SI-7(1) SI-7(12) SI-7(15) SI-7(6) | A.8.19 A.5.16 A.5.2 A.5.4 A.5.8 A.5.14 A.5.22 A.5.23 A.8.21 A.8.29 A.8.30 | ||||
| CM0035 | Protect Authenticators | Authenticators and associated authenticator material, including passwords, secret and private keys, tokens, biometric templates, shared secrets, certificates, and trust-store entries, must be protected against unauthorized modification and, where the material is confidential, unauthorized disclosure throughout their lifecycle. Disclosure of secret authenticator material may enable adversaries to impersonate legitimate users or systems. Unauthorized modification of authenticators, certificates, or trust information can deny access to legitimate entities, substitute adversary-controlled credentials, or corrupt the trust basis of mission authentication mechanisms. Protection must apply to authenticators at rest, in transit, and in use, and must extend to all forms and storage locations, including credential databases, configuration files, embedded device credentials, hardware security tokens, and cryptographic key stores. Authenticator protection is a prerequisite for the effectiveness of any authentication-based access control; an authentication system whose authenticators are unprotected provides no meaningful security regardless of the strength of the underlying authentication protocol. | AC-17(6) AC-3(11) CM-3(6) IA-4(9) IA-5 IA-5(6) PL-8 PL-8(1) SA-3 SA-4(5) SA-8 SA-8(13) SA-8(19) SC-16 SC-16(1) SC-8(1) | A.8.4 A.5.16 A.5.17 A.5.8 A.5.2 A.5.8 A.8.25 A.8.31 A.8.27 A.8.28 A.5.33 | ||||
| CM0032 | On-board Intrusion Detection & Prevention | An on-board intrusion detection and prevention system (IDS/IPS) monitors mission-critical spacecraft components and systems, generates and stores audit records, and supports mission-approved responses to detected threats. Depending on the mission architecture, threat, and availability of ground support, responses may be autonomous, ground-directed, or a combination of both. The system should address both known attack patterns and previously unseen anomalous behavior through complementary signature-based and behavior- or anomaly-based detection methods. Machine learning or adaptive technologies may be used when their performance, resource consumption, and failure behavior have been validated for the mission environment. Detection and response coverage should address applicable adversary activities across the attack lifecycle, including initial access, execution, persistence, defense evasion, and exfiltration. The on-board IDS/IPS must be integrated with the spacecraft's traditional fault management system to provide a unified approach to anomaly response, ensuring that cyber-triggered responses are compatible with fault management logic and do not produce unintended effects or fratricide against the spacecraft's own systems; countermeasures that are incompatible with fault management are considered unsafe and must not be executed autonomously. The response hierarchy must prioritize vehicle safety and continued mission operations. Advanced containment or deception responses may be considered when they can be executed without unacceptable mission risk. The system should preserve evidence that supports post-event analysis, threat characterization, and potential attribution by authorized ground support. | AU-14 AU-2 AU-3 AU-3(1) AU-4 AU-4(1) AU-5 AU-5(2) AU-5(5) AU-6(1) AU-6(4) AU-8 AU-9 AU-9(2) AU-9(3) CA-7(6) CM-11(3) CP-10 CP-10(4) IR-4 IR-4(11) IR-4(12) IR-4(14) IR-4(5) IR-5 IR-5(1) PL-8 PL-8(1) RA-10 RA-3(4) SA-8(21) SA-8(22) SA-8(23) SC-16(2) SC-32(1) SC-5 SC-5(3) SC-7(10) SC-7(9) SI-10(6) SI-16 SI-17 SI-3 SI-3(10) SI-3(8) SI-4 SI-4(1) SI-4(10) SI-4(11) SI-4(13) SI-4(16) SI-4(17) SI-4(2) SI-4(23) SI-4(24) SI-4(25) SI-4(4) SI-4(5) SI-4(7) SI-6 SI-7(17) SI-7(8) | A.8.15 A.8.15 A.8.6 A.8.17 A.5.33 A.8.15 A.8.15 A.5.29 A.5.25 A.5.26 A.5.27 A.5.8 A.5.7 A.8.12 A.8.7 A.8.16 A.8.16 A.8.16 A.8.16 | ||||