________ is the concept that tells us about the replacement of every alphabet by another alphabet and the entire series gets 'shifted' by some fixed quantity.

A) Block Cipher

B) Shift Cipher

C) Rolling Cipher

D) Playfair Cipher

Correct Answer : Shift Cipher

Explanation : Shift Cipher is the concept that tells us about the replacement of every alphabet by another alphabet and the entire series gets ‘shifted’ by some fixed quantity (which is the key) between 0 and 25.