Control statement
Employ a diverse set of information technologies for the following system components in the implementation of the system: [Organization-defined: system components].
Discussion
Increasing the diversity of information technologies within organizational systems reduces the impact of potential exploitations or compromises of specific technologies. Such diversity protects against common mode failures, including those failures induced by supply chain attacks. Diversity in information technologies also reduces the likelihood that the means adversaries use to compromise one system component will be effective against other system components, thus further increasing the adversary work factor to successfully complete planned attacks. An increase in diversity may add complexity and management overhead that could ultimately lead to mistakes and unauthorized configurations.
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 Heterogeneity 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
a diverse set of information technologies is employed for [Organization-defined: system components] in the implementation of the system.
Examine
- System and communications protection policy
- system design documentation
- system configuration settings and associated documentation
- list of technologies deployed in the system
- acquisition documentation
- acquisition contracts for system components or services
- system security plan
- other relevant documents or records
Interview
- System/network administrators
- organizational personnel with information security responsibilities
- organizational personnel with system acquisition, development, and implementation responsibilities
Test
- Mechanisms supporting and/or implementing the employment of a diverse set of information technologies
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-29(1) — Virtualization Techniques
Employ virtualization techniques to support the deployment of a diversity of operating systems and applications that are changed [Organization-defined: frequency].
Official discussion
While frequent changes to operating systems and applications can pose significant configuration management challenges, the changes can result in an increased work factor for adversaries to conduct successful attacks. Changing virtual operating systems or applications, as opposed to changing actual operating systems or applications, provides virtual changes that impede attacker success while reducing configuration management efforts. Virtualization techniques can assist in isolating untrustworthy software or software of dubious provenance into confined execution environments.
Organization-defined parameters (1)
Assessment objectives and methods
virtualization techniques are employed to support the deployment of a diverse range of operating systems and applications that are changed [Organization-defined: frequency].
Examine
- System and communications protection policy
- configuration management policy and procedures
- system design documentation
- system configuration settings and associated documentation
- system architecture
- list of operating systems and applications deployed using virtualization techniques
- change control records
- configuration management records
- system audit records
- system security plan
- other relevant documents or records
Interview
- System/network administrators
- organizational personnel with information security responsibilities
- organizational personnel with responsibilities for implementing approved virtualization techniques to the system
Test
- Mechanisms supporting and/or implementing the employment of a diverse set of information technologies
- mechanisms supporting and/or implementing virtualization techniques
Authoritative sources
Bare Metal Cyber is an independent educational publisher and is not affiliated with or endorsed by NIST. Official control requirements and interpretations remain with NIST and the responsible authorizing organization.