Step $1.$ Find out the data you need to work on

$$Use the last $3$ digits of your student ID to identify the row that contains $10-$bit key, and plain text you need. Determine all intermediate answers and find out the ciphertext.

Last $3-$digit of your ID $10-$bit key Plain Text

$331101001010001100001$

$890101001010001100010$

$028101001010001100011$

$733101001010001100100$

$081101001010001100101$

$092101001010001100110$

$487101001010001100111$

$704101001010001101000$

$263101001010001101001$

$257101001010001101010$

$833101001010001101011$

$260101001010001101100$

$810101001010001101101$

$349101001010001101110$

$213101001010001101111$

$388101001010001110000$

$924101001010001110001$

$435101001010001110010$

$121101001010001110011$

$816101001010001110100$

$673101001010001110101$

$429101001010001110110$

$144101001010001110111$

$383101001010001111000$

$450101001010001111001$

$829101001010001111010$

$940101001010001000001$

$555101001010001000010$

$624101001010001000011$

$189101001010001000100$

$347101001010001000101$

$335101001010001000110$

$452101001010001000111$

$826101001010001001000$

$363101001010001001001$

Step $2.$ S$-$DES Subkeys

$$In Exercise#$1,$ you obtain the $2$ subkeys using five steps $($for details of each step, please refer to the exercise notes$).$ In the table below, write down your $10-$bit key, and complete the table by determining the resulting data and subkeys.

Write your $10-$bit key:

Step Hint Resulting data Write $$K$1$ or $$K$2$ if the resulting data is a subkey $($leave it empty if it is not$)$

Step $1$ Use P$10...$

Step $2$ Split and rotate...

Step $3$ Join.. and use P$8$

Step $4$ Rotate....

Step $5$ Join...and use P$8$

Step $3.$ S$-$DES Encryption

$$In Exercise#$2,$ you obtain the ciphertext using fifteen steps $($for details of each step, please refer to the exercise notes$).$ In the table below, write down your $8-$bit plain text; complete the table by determining the resulting data and ciphertext.

Write your $8-$bit plain text:

Step Hint

Resulting data

Step $1$ Use IP$...$

Step $2$ Split and use EP $...$

Step $3$ XOR with a subkey...

Step $4$ Split and use S$0$ and S$1...$

Step $5$ Use P$4$

Step $6$ Apply XOR on two sets of data

Step $7$ Join two sets of data

Step $8$ Swap...

Step $9$ Split and use EP $...$

Step $10$ XOR with a subkey...

Step $11$ Split and use S$0$ and S$1...$

Step $12$ Use P$4$

Step $13$ Apply XOR on two sets of data

Step $14$ Join two sets of data

Step $15$ Use IP$-1$ to obtain the ciphertext