What are the measures and controls to protect classified information known as?

The term that describes the measures and controls implemented to protect classified information is "safeguarding." This refers to a comprehensive set of actions and procedures designed to ensure the confidentiality, integrity, and availability of classified materials. Safeguarding encompasses a variety of practices, such as physical security measures, access controls, and personnel security clearances, all aimed at preventing unauthorized access or disclosure of classified information.

While other terms may be related, they do not specifically encapsulate the established protocols and safeguards mandated for classified information. "Protective measures" is a broader term that might apply to various types of security, not just classified information. "Security protocols" typically refer to specific procedures or rules for maintaining security, but they lack the comprehensive focus on classified information safeguarding. "Information control" could apply to the management of information in a general sense, but it does not specifically relate to the protection of classified data in the structured manner that safeguarding does.