Assume an attacker knows that a user$$s password is either $$wxyz$$ or $$bddf$.$ Say the user encrypts his password using:

a$)$ The substitution cipher,

b$)$ The Vigen$$re cipher using period $2,$ or

c$)$ The Vigen$$re cipher using period $3$

and the attacker sees the resulting ciphertext. Show how the attacker can determine the user$$s password, or explain why this is not possible.