ISA/IEC 62443 Cybersecurity Fundamentals Specialist — Question 47

Which type of cryptographic algorithms requires more than one key?

Answer options

• A. Block ciphers
• B. Stream ciphers
• C. Symmetric (private) key
• D. Asymmetric (public) key

Correct answer: D

Explanation

The correct answer is D, Asymmetric (public) key, because it uses a pair of keys: a public key for encryption and a private key for decryption. The other options, including symmetric key algorithms, only rely on a single key for both encryption and decryption, which is not the case with asymmetric algorithms.