Is encrypted enforced for NIST SP 800-53 Rev 5?

Yes, Because sensitive data can exist and to help protect data at rest, ensure encryption is enabled for your AWS Elastic File System (EFS).

Is kms_key_arn enforced for NIST SP 800-53 Rev 5?

Yes, Ensure AWS Elastic File Systems (AWS EFS) are encrypted using CMK. The rule is non-compliant if the EFS File System is not encrypted using CMK.

3 controls from NIST SP 800-53 Rev 5 apply to this module.

Control	Clause	Change
EFS file systems should have encryption at rest enabledefs_file_system_encrypt_data_at_rest AU-9(3)	AU-9(3)
EFS file systems should be encrypted with CMKefs_file_system_encrypted_with_cmk AU-9(3)	AU-9(3)
VPC Security groups should only allow unrestricted incoming traffic for authorized portsvpc_security_group_allows_ingress_authorized_ports SC-7	SC-7