Exercise $1($Chosen$-$PlaintextAttackontheSubstitutionCipher $(4$marks$))$

Show that the substitution cipher as defined in Module $2\mathrm{.}1$ slides is totally insecure in the chosenplaintext attack model. In particular, you should describe an attack and show that a computationally bounded adversary can easily recover the secret key of the cipher by mounting a chosenplaintextattack.

Hint:thinkof whatcanbeausefulplaintexttorevealinformationaboutthekey: