Question

Which of the following was a multi alphabet cipher widely used from the 16th century (1553) to the early 20th century (1900s)?

A Vigenere
B Caesar
C Atbash
D Scytale

Answer 1

The Vigenère Cipher is the multi alphabet cipher that was widely used between the 16th century and early 20th century.

Step-by-step explanation:

The multi alphabet cipher widely used from the 16th century (1553) to the early 20th century (1900s) is the Vigenère Cipher. This cipher employs a series of different Caesar ciphers based on the letters of a keyword. Each letter of the plaintext is shifted along the alphabet by a number of places defined by a corresponding letter in the keyword, effectively using multiple alphabets to encrypt the message. It was considered secure for a long period because of its complexity compared to monoalphabetic ciphers.