Certified Encryption Specialist (ECES) v3 — Question 1

Tom is explaining historical cryptography to a class of security students. Which of the following ciphers is a subset of the Vigenère cipher?

Answer options

• A. Scytale
• B. Caesar
• C. Blowfish
• D. Atbash

Correct answer: C

Explanation

The correct answer is C, as Blowfish is a modern symmetric-key block cipher that can be seen as an evolution of earlier methods, but it is not a subset of the Vigenère cipher. The other options, Scytale, Caesar, and Atbash, are all classical ciphers that operate differently and do not relate directly to the Vigenère cipher structure.