CompTIA Security Plus Mock Test Q1004

Which of the following is true about asymmetric encryption?

A. A message encrypted with the private key can be decrypted by the same key
B. A message encrypted with the public key can be decrypted with a shared key.
C. A message encrypted with a shared key, can be decrypted by the same key.
D. A message encrypted with the public key can be decrypted with the private key.


Correct Answer: D
Section: Cryptography

Explanation:
Asymmetric algorithms use two keys to encrypt and decrypt data. These asymmetric keys are referred to as the public key and the private key. The sender uses the public key to
encrypt a message, and the receiver uses the private key to decrypt the message; what one key does, the other one undoes.

Incorrect Answers:
A: The message is encrypted with a public key, not with a private key.
B: The message is decrypted with a private key, not with a shared key.
C: The message is encrypted with a public key, not with a shared key.

References:
Dulaney, Emmett and Chuck Eastton, CompTIA Security+ Study Guide, 6th Edition, Sybex, Indianapolis, 2014, pp. 251-254