Practice AC.L2-3.1.19 Details

Source of Reference: The official CMMC Level 2 Assessment Guide from the Office of the Under Secretary of Defense Acquisition & Sustainment.

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AC.L2-3.1.19 – ENCRYPT CUI ON MOBILE

SECURITY REQUIREMENT

Encrypt CUI on mobile devices and mobile computing platforms.

ASSESSMENT OBJECTIVES

Determine if:

[a] mobile devices and mobile computing platforms that process, store, or transmit CUI are identified; and

[b] encryption is employed to protect CUI on identified mobile devices and mobile computing platforms.

POTENTIAL ASSESSMENT METHODS AND OBJECTS

Examine

[SELECT FROM: Access control policy; procedures addressing access control for mobile devices;system design documentation;system configuration settings and associated documentation;encryption mechanisms and associated configuration documentation;system security plan; system audit logs and records; other relevant documents or records].

Interview

[SELECT FROM: Personnel with access control responsibilities for mobile devices; system or network administrators; personnel with information security responsibilities].

Test

[SELECT FROM: Encryption mechanisms protecting confidentiality of information on mobile devices].

DISCUSSION

Organizations can employ full-device encryption or container-based encryption to protect the confidentiality of CUI on mobile devices and computing platforms. Container-based encryption provides a more fine-grained approach to the encryption of data and information including encrypting selected data structures such as files, records, or fields.

FURTHER DISCUSSION

Ensure CUI is encrypted on all mobile devices and mobile computing platforms that process, store, or transmit CUI including smartphones, tablets, and e-readers.

When CMMC requires cryptography, it is to protect the confidentiality of CUI. FIPS-validated cryptography means the cryptographic module has to have been tested and validated to meet FIPS 140-1 or-2 requirements. Simply using an approved algorithm is not sufficient – the module (software and/or hardware) used to implement the algorithm must be separately validated under FIPS 140. Accordingly, FIPS-validated cryptography is required to meet CMMC practices that protect CUI when transmitted or stored outside the protected environment of the covered contractor information system (including wireless/remote access). Encryption used for other purposes, such as within applications or devices within the protected environment of the covered contractor information system, would not need to be FIPS-validated.

This practice, AC.L2-3.1.19, requires that CUI be encrypted on mobile devices and extends three other CUI protection practices (MP.L2-3.8.1, MP.L2-3.8.2, and SC.L2-3.13.16):

• MP.L2-3.8.1 requires that media containing CUI be protected.
• MP.L2-3.8.2 limits access to CUI to authorized users.
• Finally, SC.L2-3.13.16 requires confidentiality of CUI at rest.

This practice, AC.L2-3.1.19, also leverages SC.L2-3.13.11, which specifies that the algorithms used must be FIPS-validated, and SC.L2-3.13.10, which specifies that any cryptographic keys in use must be protected.

Example

You are in charge of mobile device security. You configure all laptops to use the full-disk encryption technology built into the operating system. This approach is FIPS-validated and encrypts all files, folders, and volumes.

Phones and tablets pose a greater technical challenge with their wide range of manufacturers and operating systems. You select a proprietary mobile device management (MDM) solution to enforce FIPS-validated encryption on those devices [a,b].

Potential Assessment Considerations

• Is a list maintained of mobile devices and mobile computing platforms that are permitted to process, store, or transmit CUI [a]?
• Is CUI encrypted on mobile devices using FIPS-validated algorithms [b]?

KEY REFERENCES

• NIST SP 800-171 Rev 2 3.1.19