Crypto Key Management

Leverage best practices for crypto key management as defined by organization like NIST or the National Security Agency. Leverage only approved cryptographic algorithms, cryptographic key generation algorithms or key distribution techniques, authentication techniques, or evaluation criteria. Encryption key handling should be performed outside of the onboard software and protected using cryptography. Encryption keys should be restricted so that they cannot be read via any telecommands.

Sources

Best Segment for Countermeasure Deployment

  • Space Segment, Ground Segment, and Development Environment

NIST Rev5 Controls

D3FEND

ISO 27001

ID: CM0030
D3FEND Artifacts: 
Created: 2022/10/19
Last Modified: 2022/12/08

Techniques Addressed by Countermeasure

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ID Name Description
IA-0003 Crosslink via Compromised Neighbor Threat actors may compromise a victim spacecraft via the crosslink communications of a neighboring spacecraft that has been compromised. spacecraft in close proximity are able to send commands back and forth. Threat actors may be able to leverage this access to compromise other spacecraft once they have access to another that is nearby.
IA-0008 Rogue External Entity Threat actors may gain access to a victim spacecraft through the use of a rogue external entity. With this technique, the threat actor does not need access to a legitimate ground station or communication site.
.01 Rogue Ground Station Threat actors may gain access to a victim spacecraft through the use of a rogue ground system. With this technique, the threat actor does not need access to a legitimate ground station or communication site.
.02 Rogue Spacecraft Threat actors may gain access to a target spacecraft using their own spacecraft that has the capability to maneuver within close proximity to a target spacecraft to carry out a variety of TTPs (i.e., eavesdropping, side-channel, etc.). Since many of the commercial and military assets in space are tracked, and that information is publicly available, attackers can identify the location of space assets to infer the best positioning for intersecting orbits. Proximity operations support avoidance of the larger attenuation that would otherwise affect the signal when propagating long distances, or environmental circumstances that may present interference.
EX-0003 Modify Authentication Process Threat actors may modify the internal authentication process of the victim spacecraft to facilitate initial access, recurring execution, or prevent authorized entities from accessing the spacecraft. This can be done through the modification of the software binaries or memory manipulation techniques.
PER-0004 Replace Cryptographic Keys Threat actors may attempt to fully replace the cryptographic keys on the space vehicle which could lockout the mission operators and enable the threat actor's communication channel. Once the encryption key is changed on the space vehicle, the spacecraft is rendered inoperable from the operators perspective as they have lost commanding access. Threat actors may exploit weaknesses in the key management strategy. For example, the threat actor may exploit the over-the-air rekeying procedures to inject their own cryptographic keys.
DE-0004 Masquerading Threat actors may gain access to a victim spacecraft by masquerading as an authorized entity. This can be done several ways, including through the manipulation of command headers, spoofing locations, or even leveraging Insider's access (i.e., Insider Threat)
LM-0003 Constellation Hopping via Crosslink Threat actors may attempt to command another neighboring spacecraft via crosslink. spacecraft in close proximity are often able to send commands back and forth. Threat actors may be able to leverage this access to compromise another spacecraft.
EXF-0004 Out-of-Band Communications Link Threat actors may attempt to exfiltrate data via the out-of-band communication channels. While performing eavesdropping on the primary/second uplinks and downlinks is a method for exfiltration, some space vehicles leverage out-of-band communication links to perform actions on the space vehicle (i.e., re-keying). These out-of-band links would occur on completely different channels/frequencies and often operate on separate hardware on the space vehicle. Typically these out-of-band links have limited built-for-purpose functionality and likely do not present an initial access vector but they do provide ample exfiltration opportunity.
EXF-0007 Compromised Ground System Threat actors may compromise target owned ground systems that can be used for future campaigns or to perpetuate other techniques. These ground systems have already been configured for communications to the victim spacecraft. By compromising this infrastructure, threat actors can stage, launch, and execute an operation. Threat actors may utilize these systems for various tasks, including Execution and Exfiltration.
EXF-0008 Compromised Developer Site Threat actors may compromise development environments located within the ground system or a developer/partner site. This attack can take place in a number of different ways, including manipulation of source code, manipulating environment variables, or replacing compiled versions with a malicious one. This technique is usually performed before the target spacecraft is in orbit, with the hopes of adding malicious code to the actual FSW during the development process.
EXF-0010 Payload Communication Channel Threat actors can deploy malicious software on the payload(s) which can send data through the payload channel. Payloads often have their own communication channels outside of the main TT&C pathway which presents an opportunity for exfiltration of payload data or other spacecraft data depending on the interface and data exchange.

Space Threats Addressed by Countermeasure

ID Description
SV-AC-3 Compromised master keys or any encryption key  
SV-AC-8 Malicious Use of hardware commands - backdoors / critical commands  
SV-AC-1 Attempting access to an access-controlled system resulting in unauthorized access  
SV-AC-2 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  
SV-CF-1 Tapping of communications links (wireline, RF, network) resulting in loss of confidentiality; Traffic analysis to determine which entities are communicating with each other without being able to read the communicated information  
SV-IT-1 Communications system spoofing resulting in denial of service and loss of availability and data integrity  
SV-AC-4 Masquerading as an authorized entity in order to gain access/Insider Threat  

Low-Level Requirements

Requirement Rationale/Additional Guidance/Notes
The [organization] shall protect documentation and Controlled Unclassified Information (CUI) as required, in accordance with the risk management strategy.{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}
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.
The [organization] shall identify the key system components or capabilities that require isolation through physical or logical means.{SV-AC-6}{AC-3,SC-3,SC-7(13),SC-28(3),SC-32,SC-32(1)} Fault management and security management capabilities would be classified as mission critical and likely need separated. Additionally, capabilities like TT&C, C&DH, GNC might need separated as well.
The [organization] shall define policy and procedures to ensure that the developed or delivered systems do not embed unencrypted static authenticators in applications, access scripts, configuration files, nor store unencrypted static authenticators on function keys.{SV-AC-1,SV-AC-3}{IA-5(7)}
The [organization] shall have a two-man rule to achieve a high level of security for systems with command level access to the spacecraft.(Under this rule all access and actions require the presence of two authorized people at all times.) {SV-AC-4}{PE-3} Note: These are not spacecraft requirements but important to call out but likely are covered under other requirements by the customer.
The [organization] shall have Insider Threat Program to aid in the prevention of people with authorized access to perform malicious activities.{SV-AC-4}{PM-12,AT-2(2),IR-4(7)} Note: These are not spacecraft requirements but important to call out but likely are covered under other requirements by the customer.
The [organization], upon termination of individual employment, disables information system access within [TBD minutes] of termination.{SV-AC-4}{PS-4}
The [organization] shall produce, control, and distribute asymmetric cryptographic keys (where applicable) using NSA Certified or Approved key management technology and processes per CNSSP 12.{SC-12(3)}
The [organization] shall have physical security controls to prevent unauthorized access to the systems that have the ability to command the spacecraft.{SV-AC-4}{PE-3} Note: These are not spacecraft requirements but important to call out but likely are covered under other requirements by the customer.
The [spacecraft] shall terminate the connection associated with a communications session at the end of the session or after 3 minutes of inactivity.{SV-AC-1}{AC-12,SA-8(18),SC-10,SC-23(1),SC-23(3),SI-14,SI-14(3)}
The [spacecraft] shall protect authenticator content from unauthorized disclosure and modification.{SV-AC-1,SV-AC-3}{AC-17(6),CM-3(6),IA-5,IA-5(6),RA-5(4),SA-8(18),SA-8(19),SC-28(3)}
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)}
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)}
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)}
The [spacecraft] shall produce, control, and distribute symmetric cryptographic keys using NSA Certified or Approved key management technology and processes per CNSSP 12.{SV-AC-1,SV-AC-3}{AC-17(6),CM-3(6),SA-9(6),SC-12,SC-12(1),SC-12(2),SC-12(3)}
The [spacecraft] shall provide the capability to restrict command lock based on geographic location of ground stations.{SV-AC-1}{AC-2(11),IA-10,SI-4(13),SI-4(25)} This could be performed using command lockout based upon when the spacecraft is over selected regions. This should be configurable so that when conflicts arise, the Program can update. The goal is so the spacecraft won't accept a command when the spacecraft determines it is in a certain region.
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)}
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)}
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.
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)}
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)}
The [spacecraft] shall not employ a mode of operations where cryptography on the TT&C link can be disabled (i.e., crypto-bypass mode).{SV-AC-1,SV-CF-1,SV-CF-2}{AC-3(10),SA-8(18),SA-8(19),SC-16(2),SC-16(3),SC-40(4)}
The [spacecraft] shall incorporate backup sources for navigation and timing.{SV-IT-1}{AU-8(1),SC-45(1),SC-45(2)}
The [spacecraft] shall have fault-tolerant authoritative time sourcing for the platform's clock.{SV-IT-1}{AU-8(2),SC-45,SC-45(1),SC-45(2),SI-13} * Adopt voting schemes (triple modular redundancy) that include inputs from backup sources. Consider providing a second reference frame against which short-term changes or interferences can be compared. * Atomic clocks, crystal oscillators and/or GPS receivers are often used as time sources. GPS should not be used as the only source due to spoofing/jamming concerns.
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)}
The [spacecraft] shall maintain the ability to establish communication with the spacecraft in the event of an anomaly to the primary receive path.{SV-AV-1,SV-IT-1}{CP-8,SA-8(18),SC-47} Receiver communication can be established after an anomaly with such capabilities as multiple receive apertures, redundant paths within receivers, redundant receivers, omni apertures, fallback default command modes, and lower bit rates for contingency commanding, as examples
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}
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.
The [spacecraft] shall implement cryptographic mechanisms that achieve adequate protection against the effects of intentional electromagnetic interference.{SV-AV-1,SV-IT-1}{SA-8(19),SC-8(1),SC-40,SC-40(1)}
The [organization] shall use NIST Approved for symmetric key management for Unclassified systems; NSA Approved or stronger symmetric key management technology for Classified systems.{SV-AC-1,SV-AC-3}{SC-12,SC-12(1),SC-12(2)} FIPS-complaint technology used by the Program shall include (but is not limited to) cryptographic key generation algorithms or key distribution techniques that are either a) specified in a FIPS, or b) adopted in a FIPS and specified either in an appendix to the FIPS or in a document referenced by the FIPS. NSA-approved technology used for symmetric key management by the Program shall include (but is not limited to) NSA-approved cryptographic algorithms, cryptographic key generation algorithms or key distribution techniques, authentication techniques, or evaluation criteria.
The [organization] shall use NSA approved key management technology and processes.NSA-approved technology used for asymmetric key management by The [organization] shall include (but is not limited to) NSA-approved cryptographic algorithms, cryptographic key generation algorithms or key distribution techniques, authentication techniques, or evaluation criteria.{SV-AC-1,SV-AC-3}{SC-12,SC-12(1),SC-12(3)}
The [spacecraft] shall produce, control, and distribute asymmetric cryptographic keys using [organization]-defined asymmetric key management processes.{SV-AC-1,SV-AC-3}{SC-12,SC-12(1),SC-12(3)} In most cased the Program will leverage NSA-approved key management technology and processes.
The [spacecraft] shall internally monitor GPS performance so that changes or interruptions in the navigation or timing are flagged.{SV-IT-1}{SC-45(1)}
The [spacecraft] shall protect external and internal communications from jamming and spoofing attempts.{SV-AV-1,SV-IT-1}{SC-5,SC-40,SC-40(1)} Can be aided via the Crosslink, S-Band, and L-Band subsystems
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
The [organization] shall ensure that all viable commands are known to the mission and SV "owner.{SV-AC-8}{SI-10,SI-10(3)} This is a concern for bus re-use. It is possible that the manufacturer left previously coded commands in their syntax rather than starting from a clean slate. This leaves potential backdoors and other functionality the mission does not know about.
The [organization] shall perform analysis of critical (backdoor) commands that could adversely affect mission success if used maliciously.{SV-AC-8}{SI-10,SI-10(3)} Heritage and commercial products often have many residual operational (e.g., hardware commands) and test capabilities that are unidentified or unknown to the end user, perhaps because they were not expressly stated mission requirements. These would never be tested and their effects unknown, and hence, could be used maliciously. Test commands not needed for flight should be deleted from the flight database.
The [spacecraft] shall only use or include [organization]-defined critical commands for the purpose of providing emergency access where commanding authority is appropriately restricted.{SV-AC-8}{SI-10,SI-10(3)} The intent is protect against misuse of critical commands. On potential scenario is where you could use accounts with different privileges, could require an additional passphrase or require entry into a different state or append an additional footer to a critical command. There is room for design flexibility here that can still satisfy this requirement.