Question

Which of the following correctly defines poly alphabetic cipher?

(a) a substitution based cipher which uses multiple substitution at different positions

(b) a substitution based cipher which uses fixed substitution over entire message

(c) a transposition based cipher which uses multiple substitution at different positions

(d) a transposition based cipher which uses fixed substitution over entire message

The question was posed to me in semester exam.

Question is taken from Cryptography topic in chapter Cryptography of Data Structures & Algorithms II

Answer 1

Right choice is (a) a substitution based cipher which uses multiple substitution at different positions

Best explanation: Poly alphabetic cipher is a type of substitution cipher. It uses multiple substitution at different positions in order to cipher the plain text.