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NIST SP 800-53 Learning Center

AU-16 — Cross-organizational Audit Logging

Read the official control and assessment content, then use the separately labeled Bare Metal Cyber perspective to connect the requirement to implementation, evidence, and sustained operation.

3Enhancements
2Parameters
0Baseline memberships
3Assessment methods

AU — Audit and Accountability · NIST SP 800-53 Release 5.2.0

Official NIST control content

Control statement

Employ [Organization-defined: methods] for coordinating [Organization-defined: audit information] among external organizations when audit information is transmitted across organizational boundaries.

Official NIST discussion

Discussion

When organizations use systems or services of external organizations, the audit logging capability necessitates a coordinated, cross-organization approach. For example, maintaining the identity of individuals who request specific services across organizational boundaries may often be difficult, and doing so may prove to have significant performance and privacy ramifications. Therefore, it is often the case that cross-organizational audit logging simply captures the identity of individuals who issue requests at the initial system, and subsequent systems record that the requests originated from authorized individuals. Organizations consider including processes for coordinating audit information requirements and protection of audit information in information exchange agreements.

Official OSCAL parameters

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.

methodsmethods for coordinating audit information among external organizations when audit information is transmitted across organizational boundaries are defined;
audit informationaudit information to be coordinated among external organizations when audit information is transmitted across organizational boundaries is defined;
Original Bare Metal Cyber perspective

From control text to operational evidence

Use Cross-organizational Audit Logging 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 audit event design, trustworthy collection, retention, review, and investigation support.

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

  • logging standards and event-selection decisions
  • sample audit records and retention settings
  • time-synchronization evidence
  • alert and review records

Common failure patterns

  • collecting logs without defined use cases
  • critical events missing from the audit trail
  • retention shorter than investigative needs
  • logs accessible to the same administrators being monitored

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?
Official NIST SP 800-53A content

Assessment objectives and methods

Show the assessment objective

[Organization-defined: methods] for coordinating [Organization-defined: audit information] among external organizations when audit information is transmitted across organizational boundaries are employed.

Examine

  • Audit and accountability policy
  • system security plan
  • privacy plan
  • procedures addressing methods for coordinating audit information among external organizations
  • system design documentation
  • system configuration settings and associated documentation
  • system audit records
  • other relevant documents or records

Interview

  • Organizational personnel with responsibilities for coordinating audit information among external organizations
  • organizational personnel with information security and privacy responsibilities

Test

  • Mechanisms implementing cross-organizational auditing
Official relationships

Related controls

These relationships come from the official OSCAL catalog. They indicate useful dependencies or context, not automatic inheritance or equivalence.

Official NIST enhancements

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.

Official NIST control enhancement

AU-16(1) — Identity Preservation

Preserve the identity of individuals in cross-organizational audit trails.

Official discussion

Identity preservation is applied when there is a need to be able to trace actions that are performed across organizational boundaries to a specific individual.

Assessment objectives and methods

the identity of individuals in cross-organizational audit trails is preserved.

Examine

  • Audit and accountability policy
  • system security plan
  • privacy plan
  • procedures addressing cross-organizational audit trails
  • system design documentation
  • system configuration settings and associated documentation
  • system audit records
  • other relevant documents or records

Interview

  • Organizational personnel with cross-organizational audit responsibilities
  • organizational personnel with information security and privacy responsibilities

Test

  • Mechanisms implementing cross-organizational auditing (if applicable)
Related controls
Official NIST control enhancement

AU-16(2) — Sharing of Audit Information

Provide cross-organizational audit information to [Organization-defined: organizations] based on [Organization-defined: cross-organizational sharing agreements].

Official discussion

Due to the distributed nature of the audit information, cross-organization sharing of audit information may be essential for effective analysis of the auditing being performed. For example, the audit records of one organization may not provide sufficient information to determine the appropriate or inappropriate use of organizational information resources by individuals in other organizations. In some instances, only individuals’ home organizations have the appropriate knowledge to make such determinations, thus requiring the sharing of audit information among organizations.

Organization-defined parameters (2)
organizationsorganizations with which cross-organizational audit information is to be shared are defined;
cross-organizational sharing agreementscross-organizational sharing agreements to be used when providing cross-organizational audit information to organizations are defined;
Assessment objectives and methods

cross-organizational audit information is provided to [Organization-defined: organizations] based on [Organization-defined: cross-organizational sharing agreements].

Examine

  • Audit and accountability policy
  • system security plan
  • privacy plan
  • procedures addressing cross-organizational sharing of audit information
  • information sharing agreements
  • other relevant documents or records

Interview

  • Organizational personnel with responsibilities for sharing cross-organizational audit information
  • organizational personnel with information security and privacy responsibilities
Related controls
Official NIST control enhancement

AU-16(3) — Disassociability

Implement [Organization-defined: measures] to disassociate individuals from audit information transmitted across organizational boundaries.

Official discussion

Preserving identities in audit trails could have privacy ramifications, such as enabling the tracking and profiling of individuals, but may not be operationally necessary. These risks could be further amplified when transmitting information across organizational boundaries. Implementing privacy-enhancing cryptographic techniques can disassociate individuals from audit information and reduce privacy risk while maintaining accountability.

Organization-defined parameters (1)
measuresmeasures to disassociate individuals from audit information transmitted across organizational boundaries are defined;
Assessment objectives and methods

[Organization-defined: measures] are implemented to disassociate individuals from audit information transmitted across organizational boundaries.

Examine

  • Audit and accountability policy
  • system security plan
  • privacy plan
  • procedures addressing cross-organizational sharing of audit information
  • policy and/or procedures regarding the deidentification of PII
  • system design documentation
  • system configuration settings and associated documentation
  • system audit records
  • other relevant documents or records

Interview

  • Organizational personnel with responsibilities for sharing cross-organizational audit information
  • organizational personnel with information security and privacy responsibilities

Test

  • Mechanisms implementing disassociability
Source record

Authoritative sources