Which of the following types of cryptography is being used here for the key exchange?

A company uses PGP to ensure that sensitive email is protected. Which of the following types of
cryptography is being used here for the key exchange?

A.
Symmetric

B.
Session-based

C.
Hashing

D.
Asymmetric

Explanation:
PGP combines symmetric-key encryption and public-key encryption. The message is encrypted
using a symmetric encryption algorithm, which requires a symmetric key. Each symmetric key is
used only once and is also called a session key.