Implement the security design principle of clear abstractions.
| ID | Name | Description | D3FEND | |
| ID | Description | |
| SV-MA-3 |
Attacks on critical software subsystems Attitude Determination and Control (AD&C) subsystem determines and controls the orientation of the satellite. Any cyberattack that could disrupt some portion of the control loop - sensor data, computation of control commands, and receipt of the commands would impact operations Telemetry, Tracking and Commanding (TT&C) subsystem provides interface between satellite and ground system. Computations occur within the RF portion of the TT&C subsystem, presenting cyberattack vector Command and Data Handling (C&DH) subsystem is the brains of the satellite. It interfaces with other subsystems, the payload, and the ground. It receives, validate, decodes, and sends commands to other subsystems, and it receives, processes, formats, and routes data for both the ground and onboard computer. C&DH has the most cyber content and is likely the biggest target for cyberattack. Electrical Power Subsystem (EPS) provides, stores, distributes, and controls power on the satellite. An attack on EPS could disrupt, damage, or destroy the satellite. |
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| Requirement | Rationale/Additional Guidance/Notes |
|---|---|
| The [organization] shall require the developer to ensure that spacecraft interfaces are simple and well-defined and that functions provide a consistent and intuitive view of the data and how the data is managed.{SA-8(1)} | The clarity and simplicity of system interfaces combined with a precise definition of their functional behavior promotes ease of analysis, inspection, and testing as well as the correct and secure use of the system. |
| The [spacecraft] software subsystems shall provide non-identical methods, or functionally independent methods, for commanding a mission critical function when the software is the sole control of that function.{SV-MA-3,SV-AV-7}{AC-3(2)} | |
| The [spacecraft] software subsystems shall provide two independent and unique command messages to deactivate a fault tolerant capability for a critical or catastrophic hazard.{SV-MA-3,SV-AV-7}{AC-3(2)} | |
| The [organization] shall implement a security architecture and design that provides the required security functionality, allocates security controls among physical and logical components, and integrates individual security functions, mechanisms, and processes together to provide required security capabilities and a unified approach to protection.{SV-MA-6}{PL-7,SA-2,SA-8,SA-8(1),SA-8(2),SA-8(3),SA-8(4),SA-8(5),SA-8(6),SA-8(7),SA-8(9),SA-8(11),SA-8(13),SA-8(19),SA-8(29),SA-8(30),SC-32,SC-32(1)} | |
| The [spacecraft] software subsystems shall provide independent mission/cyber critical threads such that any one credible event will not corrupt another mission/cyber critical thread.{SV-MA-3,SV-AV-7}{SC-3} | |
| The [spacecraft] software subsystems shall accept [Program defined hazardous] commands only when prerequisite checks are satisfied.{SV-MA-3,SV-AV-7}{SI-10} | |
| The [spacecraft] software subsystems 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-MA-3,SV-AV-7}{SI-10} | |
| The [spacecraft] software subsystems shall perform prerequisite checks for the execution of hazardous commands.{SV-MA-3,SV-AV-7}{SI-10} | |
| The [spacecraft] software subsystems shall discriminate between valid and invalid input into the software and rejects invalid input.{SV-MA-3,SV-AV-7}{SI-10,SI-10(3)} | |
| The [spacecraft] software subsystems shall properly handle spurious input and missing data.{SV-MA-3,SV-AV-7}{SI-10,SI-10(3)} | |
| The [spacecraft] software subsystems shall validate a functionally independent parameter prior to the issuance of any sequence that could remove an inhibit or perform a hazardous action.{SV-MA-3,SV-AV-7}{SI-10(3)} | |
| The [spacecraft] mission/cyber critical commands shall be "complex" and/or diverse from other commands so that a single bit flip could not transform a benign command into a hazardous command.{SV-MA-3,SV-AV-7}{SI-10(5)} | |
| The [spacecraft] software subsystems shall provide at least one independent command for each operator-initiated action used to shut down a function leading to or reducing the control of a hazard.{SV-MA-3,SV-AV-7}{SI-10(5)} | |
| The [spacecraft] shall have failure tolerance on sensors used by software to make mission-critical decisions.{SV-MA-3,SV-AV-7}{SI-13,SI-17} | |
| The [spacecraft] software subsystems shall detect and recover/transition from detected memory errors to a known cyber-safe state.{SV-MA-3,SV-AV-7}{SI-17} | |
| The [spacecraft] software subsystems shall initialize the spacecraft to a known safe state.{SV-MA-3,SV-AV-7}{SI-17} | |
| The [spacecraft] software subsystems shall operate securely in off-nominal power conditions, including loss of power and spurious power transients.{SV-MA-3,SV-AV-7}{SI-17} | |
| The [spacecraft] software subsystems shall perform an orderly, controlled system shutdown to a known cyber-safe state upon receipt of a termination command or condition.{SV-MA-3,SV-AV-7}{SI-17} | |
| The [spacecraft] software subsystems shall recover to a known cyber-safe state when an anomaly is detected.{SV-MA-3,SV-AV-7}{SI-17} | |
| The [spacecraft] software subsystems shall safely transition between all predefined, known states.{SV-MA-3,SV-AV-7}{SI-17} |
| ID | Name | Description | |
|---|---|---|---|