Hi, Ed,
Encryption at rest is done with self-encrypting drives (SEDs) on Cisco's C-Series (rack), S-Series (dense storage rack), and HyperFlex (hyperconverged rack) servers. SEDs are not supported on B-Series (blade) servers, so there's no encryption at rest support there.
UCS has no native encryption in transit capability.
Here's a link with government certification info for Cisco products: Global Government Certifications - Cisco. Notice that UCS is compliant with Common Criteria (https://www.niap-ccevs.org/Product/PCL.cfm?par303=Cisco%20Systems%2C%20Inc) among others.
HTH,
Phil
PS: The UCS hardening guide may be of interest: https://www.cisco.com/c/en/us/about/security-center/ucs-hardening.html