please help with this one thank you

$(1$ point$)$ This question concerns block cipher modes. We will use a simple affine cipher, which can be expressed in $C$ as follows.

char cipher$($unsigned char block, char key$)$

$\{$

return $($key$+11*$block$)\%256$;

$\}$

The inverse of this cipher is shown below.

char inv$\_$cipher$($unsigned char block, char key$)$

$\{//163$ is the inverse of $11$mod$256$

return block$-$key$+256))\%256$;

$\}$

Note that the block size is $8$ bits, which is one byte $($and one ASCII character$).$ We will work with the fixed key $0$x$08.$

We now decrypt various ciphertexts using modes for this cipher. In every case in which the mode requires an IV$,$ the IV will be $0$xAA. In the case of

CTR mode, we use a $($nonce $||$ counter$)$ arrangement in which the nonce is the left $5$ bits of $0AA$ and the counter is a $3$ bit counter that begins at $0.$ In

all of the problems given below, one character is one block. Each character of the plaintext should be regarded as its corresponding ASCII code. The

ciphertext is given in hexadecimal.

a$)$ Decrypt the ciphertext $"24393$F$0$F$0704"$ using CTR mode. Please enter your answer in ASCII characters $($aka words$).$

b$)$ Decrypt the ciphertext $"AC8BC2A1F9"$ using ECB mode. Please enter your answer in ASCII characters $($aka words$).$

c$)$ Decrypt the ciphertext $"3$BF$8$DEF$9$C$8"$ using CFB mode. Please enter your answer in ASCII characters $($aka words$).$

d$)$ Decrypt the ciphertext $"$A$0$CC$1$FE$3$E$059"$ using CBC mode. Please enter your answer in ASCIl characters $($aka words$).$

e$)$ Decrypt the ciphertext $"25$D$66$F$245$D$29"$ using OF B mode. Please enter your answer in ASCIl characters $($aka words$).$