computer Science...

Suppose we encrypt the $($hexadecimal$)$ plain$-$text $0123456789$ ABCDEFUsing the $($hexadecimal$)$ key $133457799$BBC DFF$1.$

The first round key: K$1=000110110000001011101111111111000111000001110010$

Find out the following output in hexadecimal format:

L$0$:

$L0=01234567$

This is the left$-$hand half of the $64-$bit plain$-$text block, split into two $32-$bit segments.

R$0$:

$R0=89$ABCDEF

This is the right$-$hand half of the $64-$bit plain$-$text block, split into two $32-$ bitsegments.

$E(R0)$

$E(R0)$ expansion: $3289$ABCF DEF$01234$

The E$-$box function is applied to the right$-$hand half of the plain$-$text block $($R$0)$ toexpand it to $48$ bits.

E$($R$0)$ XOR K$1$:

E$($R$0)$ XOR K$1$: $3288$A$9$A$7$ D$9$F$11$D$12$

The expanded right$-$hand half of the plain$-$text block $(E(R0))$ is then XORed with thefirst round key $($K$1).$

S$-$box outputs $($first round$)$:

The output of the S$-$boxes $($also known as substitution boxes$)$ after the first round. InDES, there are eight S$-$boxes that take in $6-$bit inputs and output $4-$bit outputs. The inputs to the S$-$boxes are obtained by dividing the $48-$bit output of the previous step into eight $6-$bit blocks. The outputs of the S$-$boxes are then concatenated to form a $32-$bit value. The S$-$boxes $($substitution boxes$)$ are a key component of the DES algorithm. They are used to substitute the input data with a different output value.

The S$-$boxes take $6-$bit inputs and output $4-$bit outputs. The input to the S$-$boxes is obtained by dividing the $48-$bit output of the previous step into eight $6-$bit blocks. Theoutputs of the S$-$boxes are then concatenated to form a $32-$bit value.

S$-$box outputs $($first round$)=$ S$-$box values for each $6-$bit block in

$899$BF$5$F$6$F$5$C$8$F$9$B$6(48$ total blocks$).$