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MI-ARCH-01 - Mission Essential Data Flow Function

Principle

The mission should establish and maintain a current and accurate data flow diagram covering mission essential data flows, including those that pass through mission-external service providers.

Rationale

A good data flow diagram provides understanding what data is needed by the system, and how that data flows across networks and communications links. In turn, this provides essential insight to understand where particular risk to the system may emerge, and where additional scrutiny or defenses may be warranted.

Related Countermeasures

ID Name Description NIST Rev 5
CM0001 Protect Sensitive Information Space mission sensitive information spans a broad attack surface and must be inventoried, classified, and protected at a level commensurate with its sensitivity across every location where it resides, including ground systems, contractor networks, and remote access environments. Sensitive material typically includes functional and performance specifications, interface control documents (ICDs), command and telemetry (C&T) databases, uplink protection schemes including disable and bypass features, fault management logic, scripts, simulation and rehearsal results, failure and anomaly resolution records, and architecture and software documentation. Each information type must be assigned a protection level, such as unclassified, controlled, proprietary, or classified, and access must be restricted to personnel with defined roles and a verified need to know. Sensitive data shall be protected at rest and in transit using encryption or other mission-approved safeguards commensurate with its classification, sensitivity, threat exposure, and operational constraints. DLP capabilities shall be applied to systems and data flows where they are technically feasible and effective, with alternative access controls, monitoring, or information-flow protections used where conventional DLP technology is not suitable. Ongoing configuration management must track, control, and document all changes to command procedures and critical database content to prevent unauthorized modification and mission degradation. AC-25 AC-3(11) AC-4(23) AC-4(25) AC-4(6) CA-3 CM-12 CM-12(1) PL-8 PL-8(1) PM-11 PM-17 SA-3 SA-3(1) SA-3(2) SA-4(12) SA-5 SA-8 SA-8(19) SA-9(7) SC-16 SC-16(1) SC-8(1) SC-8(3) SI-12 SI-21 SI-23 SR-12 SR-7
CM0020 Threat modeling Threat modeling is a structured analytical process that identifies, enumerates, and prioritizes potential threats to a system by systematically examining assets, trust boundaries, data flows, and adversary capabilities relative to the system's architecture. Applied in combination with attack surface analysis and vulnerability analysis, threat modeling produces an integrated picture of where the system is most exposed and what the consequences of successful exploitation would be. Analysis should draw on findings from similar systems, components, or services where applicable, leveraging documented threat experience from comparable missions or architectures to avoid re-learning known lessons. The outputs of threat modeling must directly inform design decisions throughout the development process, with attack surface reduction treated as a design objective rather than a post-development hardening activity: interfaces, services, protocols, and code paths that are not necessary to mission function should be eliminated or constrained before they become embedded in the architecture. Threat model artifacts should be treated as living documents, updated as the system design evolves and as new threat intelligence becomes available. CA-3 CM-4 CP-2 PL-8 PL-8(1) RA-3 SA-11 SA-11(2) SA-11(3) SA-11(6) SA-15(6) SA-15(8) SA-2 SA-3 SA-4(9) SA-8 SA-8(25) SA-8(30)
CM0022 Criticality Analysis Criticality analysis is a structured engineering process that identifies the mission functions, system components, and data flows whose compromise, degradation, or loss would most severely impact mission success, crew safety, or operational continuity. The outputs of this analysis directly drive security investment prioritization: components and functions assessed as most critical receive the most rigorous design-phase protections, supply chain scrutiny, and operational security controls, while lower-criticality elements are protected proportionately. Criticality analysis findings should inform the application of complementary security design principles, including network and functional segmentation and least-privilege access control, to isolate critical components from less-trusted system elements and reduce the consequence of compromise elsewhere in the system. Supply chain protection resources and oversight rigor should be explicitly allocated in proportion to component criticality, ensuring that the most mission-essential hardware and software receive the most intensive sourcing controls, provenance verification, and supplier oversight. Criticality analysis must be initiated early in the system design process and updated as the architecture evolves, threat intelligence changes, or operational experience reveals previously unrecognized dependencies. CM-4 CP-2 CP-2(8) PL-7 PL-8 PL-8(1) PM-11 PM-17 PM-30 PM-30(1) PM-32 RA-3 RA-3(1) RA-9 SA-11 SA-11(3) SA-15(3) SA-2 SA-3 SA-4(5) SA-4(9) SA-8 SA-8(25) SA-8(3) SA-8(30) SC-32(1) SC-7(29) SR-1 SR-2 SR-2(1) SR-3 SR-3(2) SR-3(3) SR-5(1) SR-7
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)
CM0073 Traffic Flow Analysis Defense Traffic flow analysis attacks enable adversaries to derive operationally significant intelligence from observable transmission characteristics, including message timing, volume, duration, periodicity, and routing information, without decrypting the content of communications. Even when link encryption is in place, unprotected traffic patterns can reveal spacecraft operational schedules, command activity, contact windows with specific ground stations, and anomalous events that provide adversaries with actionable mission intelligence. Traffic flow analysis defense encompasses a set of techniques applied to protect the confidentiality of transmission metadata on telemetry, tracking, and commanding (TT&C) and data links, as well as onboard communications where applicable. Applicable techniques include padding transmissions to normalize message lengths and volumes, introducing artificial traffic during idle periods to obscure true contact patterns and event timing, obfuscating routing information and endpoint identities, varying transmission periodicity to defeat statistical pattern recognition, and frustrating traffic volume and duration analysis through active obfuscation methods. These controls are a complement to, but distinct from, cryptographic content protection, and should be applied based on a threat-informed assessment of the value of traffic metadata to potential adversaries and their collection capabilities. SC-8 SI-4(15)
CM0070 Alternate Communications Paths Establishing alternate communications paths for spacecraft and ground system operations reduces the likelihood that a single adversarial event, physical disruption, or technical failure will deny all mission communications. Reliance on a single communications pathway creates a single point of failure that adversaries can exploit through jamming, denial of service against ground infrastructure, physical disruption of a ground station, or compromise of network connectivity, any of which could result in complete loss of commanding and telemetry capability. Alternate paths must be assessed end to end for shared failure modes and operational dependencies. Differences in frequency, ground station, relay service, or network provider provide meaningful resilience only when the paths do not remain dependent on the same critical spacecraft, ground, management, or service infrastructure. The selection and configuration of alternate paths must be governed by the mission's concept of operations (CONOPS), which defines the conditions under which each path is used, the priority and switchover procedures between paths, and the minimum communications capability that must be maintained to satisfy mission safety and operational continuity requirements. AC-17 CP-2 CP-4(2) CP-8(3) PL-8 PL-8(1) SC-47
CM0071 Communication Physical Medium The physical medium selected for ground segment networking directly affects the mission's vulnerability to passive interception, traffic flow analysis, and electromagnetic eavesdropping, making medium selection a security design decision that must be informed by the mission's threat model. Fiber optic cabling transmits data optically and does not produce the same conducted or radiated electrical emanations as copper cabling, reducing exposure to proximity-based electromagnetic collection. Fiber may still be intercepted through physical access, optical coupling, compromised patch points, or endpoint equipment, and medium selection alone does not conceal traffic timing or volume from an observer with access to the link or its endpoints. Fiber should therefore be considered where the threat model identifies electromagnetic emanation or physical-medium interception risk, while cryptographic and physical protections remain applicable, particularly for links carrying mission-sensitive data such as command uplink traffic, cryptographic key material, or mission planning data. The selection of physical medium should be treated as a threat-informed engineering decision evaluated for each network segment based on the sensitivity of the data carried, the physical accessibility of the cabling, and the threat environment of the facility in which the cabling is installed. PE-4 SC-8 SC-8(1) SC-8(3) SC-8(5)