SC-8(4)_conceal-or-randomize-communications

SC-8(4) Conceal or Randomize Communications

Enhancement of: SC-8

High-Level Description

Family: System and Communications Protection (SC) Framework: NIST SP 800-53 Rev 5

Concealing or randomizing communication patterns addresses protection from unauthorized disclosure of information. Communication patterns include frequency, periods, predictability, and amount. Changes to communications patterns can reveal information with intelligence value, especially when combined with other available information related to the mission and business functions of the organization. Concealing or randomizing communications prevents the derivation of intelligence based on communications patterns and applies to both internal and external networks or links that may be visible to individuals who are not authorized users. Encrypting the links and transmitting in continuous, fixed, or random patterns prevents the derivation of intelligence from the system communications patterns. Alternative physical controls include protected distribution systems.

What to Check

• Verify SC-8(4) Conceal or Randomize Communications is documented in SSP
• Confirm control is operating effectively
• Review evidence of continuous monitoring for SC-8(4)
• Verify enhancement builds upon base control SC-8

How to Test

Step 1: Review Documentation

Examine the System Security Plan (SSP) and related artifacts for SC-8(4) implementation details. Verify the organization has documented how this control is satisfied.

Step 2: Validate Implementation

# For cloud environments, use cloud-audit-mcp tools
# For on-premises, review system configurations directly

# Example: Check if account management policies exist
grep -r "account.management\|access.control" /etc/security/ 2>/dev/null

Step 3: Test Operating Effectiveness

Verify the control is actively functioning, not just documented. Check logs, configurations, and operational evidence.

Tools

Remediation Guide

Control Statement

Implement cryptographic mechanisms to conceal or randomize communication patterns unless otherwise protected by [organization-defined].

Implementation Guidance

Concealing or randomizing communication patterns addresses protection from unauthorized disclosure of information. Communication patterns include frequency, periods, predictability, and amount. Changes to communications patterns can reveal information with intelligence value, especially when combined with other available information related to the mission and business functions of the organization. Concealing or randomizing communications prevents the derivation of intelligence based on communications patterns and applies to both internal and external networks or links that may be visible to individuals who are not authorized users. Encrypting the links and transmitting in continuous, fixed, or random patterns prevents the derivation of intelligence from the system communications patterns. Alternative physical controls include protected distribution systems.

Risk Assessment

CWE Categories

References

• NIST SP 800-53 Rev 5 - SC-8(4)
• NIST SP 800-53A Rev 5 (Assessment Procedures)
• NIST SP 800-53 Rev 5 Full Catalog

Checklist

• Control documented in SSP
• Implementation evidence collected
• Operating effectiveness validated
• Continuous monitoring in place
• Related controls (SC-12, SC-13) reviewed