Requirement
Encrypt CUI on mobile devices and mobile computing platforms.
Assessment Objectives
- Mobile devices and mobile computing platforms that process, store, or transmit CUI are identified
- Encryption is employed to protect CUI on identified mobile devices and mobile computing platforms
Potential Assessment Methods and Objects [NIST SP 800-171A]
Examine
- 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
- Personnel with access control responsibilities for mobile devices
- System or network administrators
- Personnel with information security responsibilities
Test
- Encryption mechanisms protecting confidentiality of information on mobile devices
Discussion [NIST SP 800-171 REV. 2]
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. Because the use of cryptography in this requirement is to protect the confidentiality of CUI, the cryptography used must meet the criteria specified in requirement SC.L2-3.13.11. This requirement, AC.L2-3.1.19, specifies that CUI be encrypted on mobile devices and extends three other CUI protection requirements (MP.L2-3.8.1, MP.L2-3.8.2, and SC.L2-3.13.16). This requirement, AC.L2-3.1.19, also leverages SC.L2-3.13.11, which specifies that the algorithms used must be FIPS-validated cryptography, and SC.L2-3.13.10, which specifies that any cryptographic keys in use must be protected.
Examples
Example 1
You are in charge of mobile device security for a company that processes CUI. 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]?
References
- NIST SP 800-171 Rev. 2 3.1.19
