In: Computer Science
If a Vigenere cipher uses the keyword CATS, what is the key used and what is the ciphertext that corresponds to the plaintext CATSCANS
Ans:
here we have,
keyword : CATS
plaintext: CATSCANS
Now, the keyword is repeated until it match the length of plaintext.
so, key is CATSCATS
Becuase, the length of the plaintext is 8, so, we made key with length of 8
Plaintext : C A T S C A N S
key : C A T S C A T S
Ciphertext : E A M K E A G K
Here we look for the character at a position where the plaintext character (row) and key character (column) is intersected.
Thefeore the Ciphertext is EAMKEAGK