Question

Discuss the process of encryption with vigener cipher with an example

Answer 1

Answer:

To encrypt a message using the Vigenère Cipher you first need to choose a keyword. As an example, we shall encrypt the plaintext "a simple example" using the keyword battista. First we must generate the keystream, by repeating the letters of the keyword until it is the same length as the plaintext.

Answer 2

Answer:

Explanation:

vVigenere Cipher is a method of encrypting alphabetic text. It uses a simple form of polyalphabetic substitution. A polyalphabetic cipher is any cipher based on substitution, using multiple substitution alphabets .The encryption of the original text is done using the Vigenère square or Vigenère table.

The table consists of the alphabets written out 26 times in different rows, each alphabet shifted cyclically to the left compared to the previous alphabet, corresponding to the 26 possible Caesar Ciphers.

At different points in the encryption process, the cipher uses a different alphabet from one of the rows.

The alphabet used at each point depends on a repeating keyword

Input : Plaintext :   GEEKSFORGEEKS

            Keyword :  AYUSH

Output : Ciphertext :  GCYCZFMLYLEIM

For generating key, the given keyword is repeated

in a circular manner until it matches the length of  

the plain text.

The keyword "AYUSH" generates the key "AYUSHAYUSHAYU"

The plain text is then encrypted using the process  

explained below.