NIST SP 800-171 Rev 2 · 3.13 System & Communications Protection

3.13.8 Encrypt CUI in transit

Implement cryptographic mechanisms to prevent unauthorized disclosure of CUI during transmission unless otherwise protected by alternative physical safeguards.

SPRS weight

3

3 points deducted from 110 when not implemented.

CMMC level

L2

Level 2 only; not among the 17 Level 1 practices.

Assessment objectives

3

From NIST SP 800-171A, each one a “determine if” an assessor answers.

What an assessor checks

NIST SP 800-171A breaks 3.13.8 into 3 objectives. Every one has to be met for the requirement to be met; a partial answer scores as not implemented.

1. [a]Determine if cryptographic mechanisms intended to prevent unauthorized disclosure of CUI are identified.
2. [b]Determine if alternative physical safeguards intended to prevent unauthorized disclosure of CUI are identified.
3. [c]Determine if either cryptographic mechanisms or alternative physical safeguards are implemented to prevent unauthorized disclosure of CUI during transmission.

Examine

[SELECT FROM: System and communications protection policy; procedures addressing transmission confidentiality and integrity; security plan; system design documentation; system configuration settings and associated documentation; system audit logs and records; other relevant documents or records].

Interview

[SELECT FROM: System or network administrators; personnel with information security responsibilities; system developer].

Test

[SELECT FROM: Cryptographic mechanisms or mechanisms supporting or implementing transmission confidentiality; organizational processes for defining and implementing alternative physical safeguards].

If it is open: POA&M eligibility

A POA&M is only permitted at a score of 88 or above, and closes in one 180-day window. Check a full gap list or compute your score.

Where 3.13.8 maps

Query it from your own tools

This page and the MacTech CMMC MCP server render the same dataset. Ask your assistant and it will answer from the methodology, not from memory.

lookup_control 3.13.8
get_assessment_objectives 3.13.8
generate_poam_entries ["3.13.8"]

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