Caesar receives "SBKFSFAFSFZF from Marcus Antonius. Decipher themessage for him.$(1)($a$)$ Caesar receives "SBKFSFAFSFZF" from Marcus Antonius. Decipher the

$3pts$

message for him.

$(2)$ Assume that we use the following table as a cipher.

$\backslash$table$[[$Original$,$A$,$B$,$C$,$D$,$E$,$F$,$G$,$H$,$I,J$,$K$,$L$,$M$,$N$,$O$,$P$,$Q$,$R$,$S$,$T$,$U$,$V$,$W$,$X$,$Y$,$Z$],[$Sent$,$X$,$Y$,$C$,$D$,$M$,$N$,$O$,$E$,$Q$,$G$,$J$,$Z$,$A$,$B$,$K$,$L$,$P$,$F$,$R$,$H$,$I,S$,$T$,$U$,$V$,$W$]]$

$($a$)$ Encrypt the message : "This is silly" using this cipher.

$3pts$

$($b$)$ Decrypt the message : $"$BKQHQRBH$".$

$3pts$