Question

In which of the following cipher the plain text and the ciphered text does not have same number of letters?

(a) keyword cipher

(b) vigenere cipher

(c) transposition cipher

(d) additive cipher

I had been asked this question during an interview for a job.

My doubt is from Cryptography in section Cryptography of Data Structures & Algorithms II

Answer 1

The correct choice is (b) vigenere cipher

Easy explanation - In transposition cipher and mono alphabetic cipher the number of letters in the plain text and ciphered text remain same. But in poly alphabetic cipher the number of letters change. So here as vigenere cipher is the only poly alphabetic cipher so it will be the answer.