PGP uses which of the following to encrypt data?

A.
An asymmetric encryption algorithm

B.
A symmetric encryption algorithm

C.
A symmetric key distribution system

D.
An X.509 digital certificate

Explanation:
Pretty Good Privacy (PGP) was designed by Phil Zimmerman as a freeware e-mail security program and was
released in 1991. It was the first widespread public key encryption program.
PGP is a complete cryptosystem that uses cryptographic protection to protect e-mail and files. It can use RSA
public key encryption for key management and use IDEA symmetric cipher for bulk encryption of data, although
the user has the option of picking different types of algorithms for these functions.
PGP can provide confidentiality by using the IDEA encryption algorithm, integrity by using the MD5 hashing
algorithm, authentication by using the public key certificates, and nonrepudiation by using cryptographically
signed messages. PGP uses its own type of digital certificates rather than what is used in PKI, but they both
have similar purposes.
Incorrect Answers:
A: PGP uses a symmetric encryption algorithm, not an asymmetric encryption algorithm to encrypt data.
C: PGP does not use a symmetric ‘key distribution system’ to encrypt data.
D: An X.509 digital certificate is used in asymmetric cryptography. PGP does not use asymmetric cryptography.

Harris, Shon, All In One CISSP Exam Guide, 6th Edition, McGraw-Hill, 2013, p. 850