CompTIA Security+ (SY0-501) — Question 479

Which of the following provides PFS?

Answer options

• A. AES
• B. RC4
• C. DHE
• D. HMAC

Correct answer: C

Explanation

DHE (Diffie-Hellman Ephemeral) is the only option that provides Perfect Forward Secrecy by generating unique key exchanges for each session. AES and RC4 are symmetric encryption algorithms and do not offer PFS, while HMAC is a method for message authentication and does not relate to key exchange.