Question

Which of the following was the first diagram substitution cipher?

(a) autokey cipher

(b) hill cipher

(c) one time pad cipher

(d) playfair cipher

I have been asked this question by my school teacher while I was bunking the class.

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

Answer 1

Right choice is (d) playfair cipher

For explanation: Poly graphic cipher is a type of substitution cipher in which substitution is performed over a block of letters. In diagram substitution, two adjacent letters are substituted simultaneously. Playfair cipher was the first diagram substitution cipher.