NIST SP 800-53 Rev. 5 SI-23 — Information Fragmentation

What this control requires

Fragment sensitive information based on specific circumstances, and distribute the fragments across multiple systems or components. This increases the difficulty for adversaries to exfiltrate valuable information, improving detection chances. However, this approach may impact the organization's ability to quickly access and retrieve the fragmented data. The extent of fragmentation depends on the information's classification, threat intelligence, and data retention strategies. This control supports the Data Security, Information Distribution capability within the System and Information Integrity family.

In plain English

Fragment sensitive information based on specific circumstances, and distribute the fragments across multiple systems or components. In practice, this means you can prove you access management-level controls on a defined cadence.

Why it matters

SP 800-53 is the catalogue every U.S. federal authorisation (FedRAMP, FISMA, CMMC) and most regulated industries point at. A missing control surfaces as a Plan of Action & Milestones (POA&M) item that an Authorizing Official must approve before the Authority To Operate is granted or renewed.

This control is rated high. Auditors expect a named owner, a remediation SLA, and a tooling artefact that evidences continuous operation.

What an auditor looks for

A 3PAO (FedRAMP) or Independent Assessor (NIST RMF) tests against NIST SP 800-53A assessment procedures. For each control they expect a documented implementation that addresses every assessment objective (Examine, Interview, Test) and an implementation summary in the System Security Plan.

Within System and Information Integrity, the assessor will trace your implementation back to the catalogue reference (Control SI-23) and look for objective evidence on the latest two assessment cycles.

How to implement

1. Write a short policy stating intent, scope and named owner.
2. Encode it as a platform guardrail — SCP, Azure Policy initiative, Organisation Policy, or repository policy.
3. Wire a monitoring signal that catches drift (CSPM rule, SIEM rule, scheduled query, Workspace alert) and ticket it.
4. Review on a documented cadence and capture the review in the risk register or compliance tracker.

Operational checklist

• Access. Document the trigger, the owner and the cadence.
• Information. Document the trigger, the owner and the cadence.
• Security. Document the trigger, the owner and the cadence.
• Data. Document the trigger, the owner and the cadence.
• Detection. Document the trigger, the owner and the cadence.
• Scope: management, information, organization, system, threat, protection, identity, retention.

Evidence to collect

• Identity Scan. IAM / IdP exports — Entra ID, Okta, IAM Identity Center, Workspace directory — showing accounts, roles, MFA state and last sign-in.

Identity analytics (Okta, SailPoint, Access Analyzer) demonstrates least-privilege. Focus: Information Fragmentation.

How it maps to other frameworks

Computed from shared tags, control component and key-operation subjects — handy when you are reconciling controls across an audit.

• NIST SP 800-171 Rev. 3 3.15.2 — System Security Plan
• ISO/IEC 27001:2022 A.5.2 — Information security roles and responsibilities
• SOC 2 (2017 TSC) P5.1 — Data Subject Access to Personal Information
• BSI C5:2020 IDM-08 — Confidentiality of authentication information

Related controls in NIST SP 800-53 Rev. 5

• Control SC-8(5) — Protected Distribution System
• Control SI-14(2) — Non-Persistent Information
• Control SI-21 — Information Refresh
• Control SI-4(20) — Privileged Users
• Control SI-10(4) — Timing Interactions
• Control SA-9(6) — Organization-Controlled Cryptographic Keys

References

• NIST Computer Security Resource Center — NIST SP 800-53 Rev. 5
• Catalogue identifier: Control SI-23

Topics: identity accessdata protectionidentity managementaccess reviewprivileged accessthreat intelligence