Q$.$How can i split the plaintext into $2$ equal parts only using the operators and memory adresses allowed in the nand$2$tetris hack assembly language?

The Feistel cipher is a symmetric block cipher encryption framework which is the basisWrite a program $($FeistelEncryption$.$asm$)$ in HACK assembly, that implements

the described Feistel encryption system. The initial key, $K_0,$ will be stored in

RAM $1$

of many modern day encryption algorithms. In this coursework you will implement

a Feistel cipher system as a software implementation in Hack Assembly.

In a Feistel cipher the plaintext, $P,$ to be encrypted is split into two equal size parts

$L_0$ and $R_0$ such that $P=L_0{R}_0.$ A function $F$ is applied to one half of the plaintext,

combined with a key, and the result is XOR'd with the other half of the plaintext.

Feistel ciphers often employ multiple rounds of this scheme. In general the scheme

works as follows, for all $i=0,$dots,$n$

$L_{i+1}=R_i$

$R_{i+1}=L_{i}o+F(R_i,K_i)$

To decrypt an encrypted message using this cipher we can apply the same procedure

in reverse. For $i=n,n-1,$dots,$0,$

$R_i=L_{i+1}$

$L_i=R_{i+1}o+F(L_{i+1},K_i)$

For this coursework we are interested in the $16-$bit Feistel cipher which uses $4$ rounds.

The function $F(A,B)=Ao+$notB.

The keys are derived from a single $8-$bit key $K_0$ such that,

$K_0=b_7{b}_6{b}_5{b}_4{b}_3{b}_2{b}_1{b}_0$

$K_1=b_6{b}_5{b}_4{b}_3{b}_2{b}_1{b}_0{b}_7$

$K_2=b_5{b}_4{b}_3{b}_2{b}_1{b}_0{b}_7{b}_6$

$K_3=b_4{b}_3{b}_2{b}_1{b}_0{b}_7{b}_6{b}_5$