Certified Ethical Hacker (CEH v11) — Question 310

User A is writing a sensitive email message to user B outside the local network. User A has chosen to use PKI to secure his message and ensure only user B can read the sensitive email. At what layer of the OSI layer does the encryption and decryption of the message take place?

Answer options

• A. Application
• B. Transport
• C. Session
• D. Presentation

Correct answer: D

Explanation

The encryption and decryption of messages using PKI occur at the Presentation layer, which is responsible for data format translation and encryption. The other layers, such as Application, Transport, and Session, do not handle encryption directly; they focus on application-specific functions, data transport, and session management respectively.