A security administrator is implementing encryption on all hard drives in an organization. Which of the following security concepts is the administrator applying?

The administrator is applying Confidentiality by encrypting all hard drives. Confidentiality ensures that only authorized individuals can access sensitive information. Encryption is a primary control for achieving confidentiality because it renders data unreadable to anyone without the correct decryption key, even if they gain unauthorized physical access to the drive. Integrity ensures data has not been altered or tampered with, often achieved through hashing or digital signatures, not encryption alone. Authentication verifies the identity of users or systems, typically through passwords, biometrics, or certificates, which is separate from data at rest encryption. Zero Trust is a security model that assumes no implicit trust inside or outside the network and requires verification for every access attempt, which is a broader strategy, not a specific concept directly addressed by disk encryption in isolation.