CMMC Practice SC.3.177
Employ FIPS-validated cryptography when used to protect the confidentiality of CUI.
Bold Coast Security Guidance
For Level 3 compliance, an organization must have practices, policy and a formal plan to implement encryption for CUI that is processed, stored, and/or transmitted on it's systems. Such a plan must include the cryptographic systems that meet the CMVP compliance standard, but also key management practices, and clear procedures to guide those with administrator responsibilities for the program.
DRAFT NIST SP 800-171 R2
Cryptography can be employed to support many security solutions including the protection of controlled unclassified information, the provision of digital signatures, and the enforcement of information separation when authorized individuals have the necessary clearances for such information but lack the necessary formal access approvals. Cryptography can also be used to support random number generation and hash generation .
Generally applicable cryptographic standards include FIPS -validated cryptography and/or NSA-approved cryptography.