Control statement
Protect external and internal [Organization-defined: organization-defined wireless links] from the following signal parameter attacks: [Organization-defined: organization-defined types of signal parameter attacks or references to sources for such attacks].
Discussion
Wireless link protection applies to internal and external wireless communication links that may be visible to individuals who are not authorized system users. Adversaries can exploit the signal parameters of wireless links if such links are not adequately protected. There are many ways to exploit the signal parameters of wireless links to gain intelligence, deny service, or spoof system users. Protection of wireless links reduces the impact of attacks that are unique to wireless systems. If organizations rely on commercial service providers for transmission services as commodity items rather than as fully dedicated services, it may not be possible to implement wireless link protections to the extent necessary to meet organizational security requirements.
Organization-defined parameters
These values must be resolved through the organization’s tailoring and governance process. Bracketed parameter references in the control text identify where a decision is required.
From control text to operational evidence
Use Wireless Link Protection as a testable risk decision. Translate the official statement into accountable people, repeatable processes, configured technology, and evidence that demonstrates the outcome over time. In this family, pay particular attention to secure architecture, boundary protection, communications protection, cryptography, and system isolation.
Implementation workflow
- Define the control boundary, responsible owner, inherited portions, and systems or processes in scope.
- Resolve each organization-defined parameter before declaring the control implemented.
- Document how the implementation satisfies every clause of the official control statement.
- Collect evidence as a normal byproduct of operation rather than only before an assessment.
- Review exceptions, changes, and monitoring results on a risk-based cadence.
Evidence examples
- network and trust-boundary diagrams
- firewall and gateway configurations
- cryptographic configuration and key records
- segmentation and isolation test results
Common failure patterns
- diagrams omit cloud and third-party paths
- encryption enabled without key governance
- flat trust zones allow unnecessary lateral movement
- boundary rules accumulate without owner review
Questions practitioners should ask
- What risk decision is this control intended to support in this system?
- Which parts are implemented locally, inherited, shared, or not applicable—and what evidence supports that decision?
- Do the documented narrative, deployed configuration, operating process, and collected evidence agree?
- What event or threshold requires the implementation to be reviewed or changed?
Assessment objectives and methods
Show the assessment objective
- SC-40[01]external [Organization-defined: wireless links] are protected from [Organization-defined: types of signal parameter attacks or references to sources for such attacks].
- SC-40[02]internal [Organization-defined: wireless links] are protected from [Organization-defined: types of signal parameter attacks or references to sources for such attacks].
Examine
- System and communications protection policy
- access control policy and procedures
- procedures addressing wireless link protection
- system design documentation
- wireless network diagrams
- system configuration settings and associated documentation
- system architecture
- list of internal and external wireless links
- list of signal parameter attacks or references to sources for attacks
- system audit records
- system security plan
- other relevant documents or records
Interview
- System/network administrators
- organizational personnel with information security responsibilities
- system developer
- organizational personnel installing, configuring, and/or maintaining the system
- organizational personnel authorizing, installing, configuring, and/or maintaining internal and external wireless links
Test
- Mechanisms supporting and/or implementing the protection of wireless links
Related controls
These relationships come from the official OSCAL catalog. They indicate useful dependencies or context, not automatic inheritance or equivalence.
Control enhancements
Enhancements add specificity, strength, or scope to the base control. Baseline badges show explicit selections in the official SP 800-53B OSCAL profiles.
SC-40(1) — Electromagnetic Interference
Implement cryptographic mechanisms that achieve [Organization-defined: level of protection] against the effects of intentional electromagnetic interference.
Official discussion
The implementation of cryptographic mechanisms for electromagnetic interference protects systems against intentional jamming that might deny or impair communications by ensuring that wireless spread spectrum waveforms used to provide anti-jam protection are not predictable by unauthorized individuals. The implementation of cryptographic mechanisms may also coincidentally mitigate the effects of unintentional jamming due to interference from legitimate transmitters that share the same spectrum. Mission requirements, projected threats, concept of operations, and laws, executive orders, directives, regulations, policies, and standards determine levels of wireless link availability, cryptography needed, and performance.
Organization-defined parameters (1)
Assessment objectives and methods
cryptographic mechanisms that achieve [Organization-defined: level of protection] against the effects of intentional electromagnetic interference are implemented.
Examine
- System and communications protection policy
- access control policy and procedures
- procedures addressing wireless link protection
- system design documentation
- wireless network diagrams
- system configuration settings and associated documentation
- system architecture
- system communications hardware and software
- security categorization results
- system audit records
- system security plan
- other relevant documents or records
Interview
- System/network administrators
- organizational personnel with information security responsibilities
- system developer
- organizational personnel installing, configuring, and/or maintaining the system
- organizational personnel authorizing, installing, configuring, and/or maintaining internal and external wireless links
Test
- Cryptographic mechanisms enforcing protections against effects of intentional electromagnetic interference
Related controls
SC-40(2) — Reduce Detection Potential
Implement cryptographic mechanisms to reduce the detection potential of wireless links to [Organization-defined: level of reduction].
Official discussion
The implementation of cryptographic mechanisms to reduce detection potential is used for covert communications and to protect wireless transmitters from geo-location. It also ensures that the spread spectrum waveforms used to achieve a low probability of detection are not predictable by unauthorized individuals. Mission requirements, projected threats, concept of operations, and applicable laws, executive orders, directives, regulations, policies, and standards determine the levels to which wireless links are undetectable.
Organization-defined parameters (1)
Assessment objectives and methods
cryptographic mechanisms to reduce the detection potential of wireless links to [Organization-defined: level of reduction] are implemented.
Examine
- System and communications protection policy
- access control policy and procedures
- procedures addressing wireless link protection
- system design documentation
- wireless network diagrams
- system configuration settings and associated documentation
- system architecture
- system communications hardware and software
- security categorization results
- system audit records
- system security plan
- other relevant documents or records
Interview
- System/network administrators
- organizational personnel with information security responsibilities
- system developer
- organizational personnel installing, configuring, and/or maintaining the system
- organizational personnel authorizing, installing, configuring, and/or maintaining internal and external wireless links
Test
- Cryptographic mechanisms enforcing protections to reduce the detection of wireless links
Related controls
SC-40(3) — Imitative or Manipulative Communications Deception
Implement cryptographic mechanisms to identify and reject wireless transmissions that are deliberate attempts to achieve imitative or manipulative communications deception based on signal parameters.
Official discussion
The implementation of cryptographic mechanisms to identify and reject imitative or manipulative communications ensures that the signal parameters of wireless transmissions are not predictable by unauthorized individuals. Such unpredictability reduces the probability of imitative or manipulative communications deception based on signal parameters alone.
Assessment objectives and methods
cryptographic mechanisms are implemented to identify and reject wireless transmissions that are deliberate attempts to achieve imitative or manipulative communications deception based on signal parameters.
Examine
- System and communications protection policy
- access control policy and procedures
- procedures addressing system design documentation
- wireless network diagrams
- system configuration settings and associated documentation
- system architecture
- system communications hardware and software
- system audit records
- system security plan
- other relevant documents or records
Interview
- System/network administrators
- organizational personnel with information security responsibilities
- system developer
- organizational personnel installing, configuring, and/or maintaining the system
- organizational personnel authorizing, installing, configuring, and/or maintaining internal and external wireless links
Test
- Cryptographic mechanisms enforcing wireless link protections against imitative or manipulative communications deception
Related controls
SC-40(4) — Signal Parameter Identification
Implement cryptographic mechanisms to prevent the identification of [Organization-defined: wireless transmitters] by using the transmitter signal parameters.
Official discussion
The implementation of cryptographic mechanisms to prevent the identification of wireless transmitters protects against the unique identification of wireless transmitters for the purposes of intelligence exploitation by ensuring that anti-fingerprinting alterations to signal parameters are not predictable by unauthorized individuals. It also provides anonymity when required. Radio fingerprinting techniques identify the unique signal parameters of transmitters to fingerprint such transmitters for purposes of tracking and mission or user identification.
Organization-defined parameters (1)
Assessment objectives and methods
cryptographic mechanisms are implemented to prevent the identification of [Organization-defined: wireless transmitters] by using the transmitter signal parameters.
Examine
- System and communications protection policy
- access control policy and procedures
- procedures addressing system design documentation
- wireless network diagrams
- system configuration settings and associated documentation
- system architecture
- system communications hardware and software
- system audit records
- system security plan
- other relevant documents or records
Interview
- System/network administrators
- organizational personnel with information security responsibilities
- system developer
- organizational personnel installing, configuring, and/or maintaining the system
- organizational personnel authorizing, installing, configuring, and/or maintaining internal and external wireless links
Test
- Cryptographic mechanisms preventing the identification of wireless transmitters
Related controls
Authoritative sources
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