CMMC Practice AC.L2-3.1.19 – Encrypt CUI on Mobile: Encrypt CUI on mobile devices and mobile computing platforms.
Links to Publicly Available Resources
Discussion [NIST SP 800-171 R2]
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.
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.