CompTIA Security+ (SY0-501) — Question 405

Which of the following implements a stream cipher?

Answer options

• A. File-level encryption
• B. IKEv2 exchange
• C. SFTP data transfer
• D. S/MIME encryption

Correct answer: D

Explanation

S/MIME encryption (option D) utilizes stream ciphers to provide confidentiality and integrity for email messages. The other options, such as File-level encryption (A), IKEv2 exchange (B), and SFTP data transfer (C), do not specifically implement stream ciphers, instead, they employ different encryption methods or protocols.