Write a program called SDESencrypt.java or sdesencrypt.py that performs the entire SDES encryption

algorithm. You may use the method you wrote in the last assignment. You will need to:

$$ add a method that takes as a parameter the $9-$bit input key and that returns a list of the four $8-$

bit sub$-$keys

$$ add a method that takes as parameters the $12-$bit input plaintext and the $9-$bit input key and

that returns the $12-$bit ciphertext

As usual, write a main method$/$main section that gets the plaintext and the key as integer values from

command line parameters. It calls the second method described above and then prints the ciphertext as

a decimal integer and as a binary string.

Last Program was

public class Sdesround $\{$

private static in assignment final int$[][]$ S$1=\{$

$\{0,0,0,0,0,0,0,0\},//$ Row $0$

$\{1,0,1,0,1,0,1,0\}//$ Row $1$

$\}$;

private static final int$[][]$ S$2=\{$

$\{4,2,4,0,2,0,0,0\},//$ Row $0$

$\{0,0,3,0,5,2,0,0\}//$ Row $1$

$\}$;

$//$ Expand $6$ bits to eight bits by the predefined method.

private static int expand$($int input$)\{$

return $($input & $0$b$100000)>>2|$

$($input & $0$b$010000)>>1|$

$($input & $0$b$001000)|$

$($input & $0$b

$($input & $0$b

$($input & $0$b

$($input & $0$b

$($input & $0$b;

$\}$

$//$ Function f$($Ri$-1,$ Ki$).$

private static int functionF$($int input, int key$)\{$

int expandedInput $=$ expand$($input$)$;

int temp $=$ expandedInput $^$ key;

$//$ Split temp into two $4-$bit values for the S$-$boxes.

int left$4=($temp $>>4)$ & $0$b$1111$;

int right$4=$ temp & $0$b$1111$;

$//$ Determine the row and column for S$1$ and S$2.$

int row$1=($left$4>>3)$ & $0$b$1$;

int row$2=($right$4>>3)$ & $0$b$1$;

int col$1=$ left$4$ & $0$b$111$;

int col$2=$ right$4$ & $0$b$111$;

$//$ Get values from S$-$boxes and concatenate.

return $($S$1[$row$1][$col S$2[$row$2][$col$2]$;

$\}$

$//$ Round of simplified DES.

public static int desRound$($int input, int key$)\{$

int L$0=($input $>>6)$ & $0$b$111111$;

int R$0=$ input & $0$b$111111$;

int R$1=$ L$0^$ functionF$($R$0,$ key$)$;

int L$1=$ R$0$; $//$ As per definition Li $=$ Ri$-1$

return $($L R$1$;

$\}$

public static void main$($String$[]$ args$)\{$

if $($args$.$length $!=2)\{$

System.out.println$("$Usage: java Sdesround bit input as integerbit key as integer$>")$;

return;

$\}$

$//$ Convert input to integers

int input $=$ Integer.parseInt$($args$[0])$;

int key $=$ Integer.parseInt$($args$[1])$;

$//$ Validate bit length

if $($input $>0$b$111111111111||$ key $>0$b$111111111)\{$

System.out.println$("$Input must be a $12-$bit integer and key must be a $9-$bit integer."$)$;

return;

$\}$

$//$ one round of simplified DES encryption

int result $=$ desRound$($input$,$ getRoundKey$($key$,1))$; $//$ Assuming round $\text{'}1\text{'}$ here for simplicity

$//$ Print binary and decimal representations of the result

System.out.println$("$Binary: $0$b$"+$ Integer.toBinaryString$($result$)+",$ decimal: $"+$ result$)$;

$\}$

$//$ Function to get the Ki for the ith round

private static int getRoundKey$($int key, int round$)\{$

$//$ Left circular shift

int roundShift $=$ round $\%9$; $//$ There are $9$ bits in the key

return $(($key $$ roundShift$)|($key $>>(9-$ roundShift$)))$ & $0$b$11111111$;

$\}$

$\}$