Which countermeasure protects confidentiality by transforming readable data into an unreadable format?

• A. Authentication
• B. Encryption
• C. Access Control
• D. Policy

Answer: (B)

Protecting confidentiality relies on converting readable data into an unreadable form so only authorized parties can recover it. Encryption applies a mathematical transform to plaintext, producing ciphertext that looks like random data unless you have the correct decryption key. With the key, the original information is restored, keeping it useless to anyone who doesn’t have access. This works whether data is being sent over a network or stored on storage media, guarding content from eavesdroppers or attackers.

Authentication is about verifying who you are, not hiding data. Access control decides who is allowed to use resources, but it doesn’t scramble the data itself. Policy sets rules and guidelines, not the technical method used to conceal information. So the mechanism that directly achieves confidentiality by turning readable data into unreadable data is encryption.