This is code I\'m currently working on learning about ciphers. During/after encr

Question

This is code I'm currently working on learning about ciphers. During/after encryption of the plain text, how would I save the cipher text in hexadecimal? Example and explanation woul be appreciated thank you.

package rccipher;

import java.util.Scanner;
import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;

public class RCCipher
{

static void output(int disp[])
{
char con[]=new char[disp.length];
for(int l=0;l<disp.length;l++)
{
con[l]=(char)disp[l];
System.out.print(con[l]);
}
}
  
  
public static void main(String args[])throws IOException
{

String text = "In cryptography, RC4 (Rivest Cipher 4 also known as ARC4 or "
+ " ARCFOUR meaning Alleged RC4) is a stream cipher. While remarkable"
+ " for its simplicity and speed in software, multiple vulnerabilities"
+ " have been discovered in RC4, rendering it insecure. It is especially"
+ " vulnerable when the beginning of the output keystream is not discarded,"
+ " or when nonrandom or related keys are used. Particularly problematic "
+ " uses of RC4 have led to very insecure protocols such as WEP.";

String key;
  
int sbox[] = new int[256];
int kgen[] = new int[256];

Scanner scan = new Scanner(System.in);

int temp=0;   

System.out.println("ORIGINAL PLAIN TEXT:");
System.out.println(text);

System.out.println(" ENTER KEY:");
key=scan.nextLine();
  
char ptextc[]=text.toCharArray();
char keyc[]=key.toCharArray();
  
int cipher[]=new int[text.length()];
int decrypt[]=new int[text.length()];
  
  
int plainTexti[]=new int[text.length()];
int keyi[]=new int[key.length()];
  
for(int i=0;i<text.length();i++)
{
plainTexti[i]=(int)ptextc[i];
}
  
for(int i=0;i<key.length();i++)
{
keyi[i]=(int)keyc[i];
}
  
for(int i=0;i<255;i++)
{
sbox[i]=i; kgen[i]=keyi[i%key.length()];   
}
  
int j=0;
  
for(int i=0;i<255;i++)
{
j=(j+sbox[i]+kgen[i])%256;   
temp=sbox[i];
sbox[i]=sbox[j];
sbox[j]=temp;
}
  
int i=0;
j=0;
int z=0;
  
  
for(int l=0;l<text.length();l++)
{
i = (l+1)%256;
j = (j+sbox[i])%256;
temp = sbox[i];
  
sbox[i] = sbox[j];
sbox[j] = temp;
  
z = sbox[(sbox[i]+sbox[j])%256];
  
cipher[l] = z^plainTexti[l];
decrypt[l] = z^cipher[l];
}
  
  
System.out.println(" CIPHER TEXT:");
output(cipher);
System.out.println(" PLAIN TEXT:");
output(decrypt);
System.out.println(" ");
}

}

Explanation / Answer

CIpher text each and every character takes maximum 1 byte i.e., 0 to 255, So it can take max 2 characters(FF). so out cipher text in hexa decimal takes 255*2 characters so 512 bytes...

import java.util.Scanner;

import java.io.BufferedReader;

import java.io.FileReader;

import java.io.IOException;

class RCCipher {

static void output(int disp[]) {

char con[] = new char[disp.length];

for (int l = 0; l < disp.length; l++) {

con[l] = (char) disp[l];

System.out.print(con[l]);

}

}

public static void main(String args[]) throws IOException {

String text = "In cryptography, RC4 (Rivest Cipher 4 also known as ARC4 or "

+ " ARCFOUR meaning Alleged RC4) is a stream cipher. While remarkable"

+ " for its simplicity and speed in software, multiple vulnerabilities"

+ " have been discovered in RC4, rendering it insecure. It is especially"

+ " vulnerable when the beginning of the output keystream is not discarded,"

+ " or when nonrandom or related keys are used. Particularly problematic "

+ " uses of RC4 have led to very insecure protocols such as WEP.";

String key;

int sbox[] = new int[256];

int kgen[] = new int[256];

Scanner scan = new Scanner(System.in);

int temp = 0;

System.out.println("ORIGINAL PLAIN TEXT:");

System.out.println(text);

System.out.println(" ENTER KEY:");

key = scan.nextLine();

char ptextc[] = text.toCharArray();

char keyc[] = key.toCharArray();

int cipher[] = new int[text.length()];

int decrypt[] = new int[text.length()];

int plainTexti[] = new int[text.length()];

int keyi[] = new int[key.length()];

for (int i = 0; i < text.length(); i++) {

plainTexti[i] = (int) ptextc[i];

}

for (int i = 0; i < key.length(); i++) {

keyi[i] = (int) keyc[i];

}

for (int i = 0; i < 255; i++) {

sbox[i] = i;

kgen[i] = keyi[i % key.length()];

}

int j = 0;

for (int i = 0; i < 255; i++) {

j = (j + sbox[i] + kgen[i]) % 256;

temp = sbox[i];

sbox[i] = sbox[j];

sbox[j] = temp;

}

int i = 0;

j = 0;

int z = 0;

for (int l = 0; l < text.length(); l++) {

i = (l + 1) % 256;

j = (j + sbox[i]) % 256;

temp = sbox[i];

sbox[i] = sbox[j];

sbox[j] = temp;

z = sbox[(sbox[i] + sbox[j]) % 256];

cipher[l] = z ^ plainTexti[l];

convertHex(cipher);

decrypt[l] = z ^ cipher[l];

}

System.out.println(" CIPHER TEXT:");

output(cipher);

System.out.println(" PLAIN TEXT:");

output(decrypt);

System.out.println(" IN CIPHER HEXADECIMAL: "+convertHex(cipher));

System.out.println(" ");

}

public static String convertHex(int cipher[]){

String enc = "";

int i=0, len = cipher.length;

for(i=0; i<len; i++){

int n = cipher[i], j=1;

char h[] = new char[2];

h[0] = '0';

h[1] = '0';

while(n!=0){

int rem = n%16;

if(rem<10)

h[j] = (char)(rem+'0');

else

h[j] = (char)(rem+55);

n = n/16;

j--;

}

enc += h[0]+""+h[1];

}

return enc;

}

}

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