import java.util.Scanner;
import java.io.IOException;
import java.io.PrintWriter;
public class Main {
//This function will decode the value of the XOR binary back
public static void decodingXorCipher(String[] XorApplied) throws IOException
{
String binaryValue ;
char cTemp;
String szOutput = "";
System.out.println("Converting Binary to ASCII Text...") ;
for(int q = 0 ; q < XorApplied.length ; q++)
{
binaryValue = XorApplied[q] ;
//This is the method that has converted binary back into ASCII text
cTemp = (binaryToChar(binaryValue));
szOutput = szOutput + cTemp ;
}
//Stores the encrypted message to a file
System.out.println(szOutput) ;
PrintWriter writer = new PrintWriter("eMessage.txt", "UTF-8");
writer.println(szOutput) ;
writer.close();
}
//Adds the XOR gate to the cipher
public static void XorCipher(String[] binaryArray , String[] keyBinaryArray)
{
//Have a placement value of value0 = 0 to pad the binary to 8 bit binary
//One by one store the data needed from array into a temporary variable
//Split each digit from the data, and store it into a different variable
//Two For Loops one runs on the length of the message (binaryArray.length) and another on the length of the binary data (8)
//compare the digits at the given address and apply the XOR Cipher
//0 and 0 gives 0
//0 and 1 gives 1
//1 and 0 gives 1
//1 and 1 gives 0
System.out.println("Applying the XOR gate...") ;
String iTemp;
String iTempBinary ;
int Length ;
String szFinished = "" ;
String[] XorApplied = new String [binaryArray.length] ;
//This loop will control the length of the message being encrypted
for(int a = 0 ; a < binaryArray.length ; a ++)
{
iTemp = binaryArray[a] ;
iTempBinary = keyBinaryArray[a] ;
Length = iTemp.length() ;
szFinished = "" ;
//Loop used for the indiviual characters in one 8 bit binary setup
//Used to apply the XOR gate to both of the binaries
for(int b = 0 ; b < 8 ; b++)
{
if(iTemp.charAt(b) == iTempBinary.charAt(b))
{
szFinished = (szFinished + "0") ;
}
else
{
szFinished = (szFinished + "1") ;
}
}
//Each of these is then stored into an array
XorApplied[a] = szFinished ;
}
//This was needed as it was throwing an IOException
try {
decodingXorCipher(XorApplied) ;
}
catch (IOException e) {
System.out.println("Error") ;
}
}
//Find binary values of each indiviual character in the message
public static void findBinary(char[] keyArray , char[] messageArray)
{
//Creates new arrays that are the same length of the message and key
String [] binaryArray = new String[messageArray.length];
String [] keyBinaryArray = new String[keyArray.length];
String iTemp;
String keyTemp ;
System.out.println("Converting Data to Binary...") ;
for(int i = 0 ; i < messageArray.length ; i++)
{
//Each element in the array is being converted to a binary value
iTemp = String.format("%8s", Integer.toBinaryString(messageArray[i])).replace(' ', '0');
//The String value is being converted into an int data type
//This is being stored into an array
binaryArray[i] = iTemp ;
//This binary element is being stored into an array
// System.out.println(binaryArray[i]) ;
}
System.out.println();
//Loop used to find ot the binary values of the key and store that into an array
for(int k = 0 ; k < keyArray.length ; k ++)
{
//Finds the binary values
keyTemp = String.format("%8s", Integer.toBinaryString(keyArray[k])).replace(' ', '0');
//Stores the int data type into an array
keyBinaryArray[k] = keyTemp ;
//System.out.println(keyBinaryArray[k]) ;
}
System.out.println("Data has been converted to Binary...") ;
XorCipher(binaryArray , keyBinaryArray) ;
}
//Taking all the variables in
public static void main(String[] args) throws IOException
{
String key = "" ;
String userMessage ;
int iRandom , iSum ;
char letter ;
String szBinary;
//Allows for the user input
Scanner szKeyboard = new Scanner(System.in) ;
System.out.println("What is the text being encrypted? ");
userMessage = szKeyboard.nextLine() ;
//Removes all the spaces
userMessage = userMessage.strip() ;
//A Random Key is Being Generated Everytime the Code is running
for(int p = 0 ; p < userMessage.length() ; p++ )
{
//This is the random process, i have taken away 32 because it would give me output values that cannot be read from the ASCII table (1-31)
iRandom = (int)(Math.random() * 223) ;
//I added 32 making sure that i do not get a vlaue less than 32
iSum = iRandom + 32 ;
//This number was changed to a binary value
szBinary = Integer.toBinaryString(iSum) ;
//The binary value was converted back into a char value
letter = (binaryToChar(szBinary));
//This is then connactnated to form the key
key = key + letter ;
}
//The key is stored into an array
char[] keyArray = key.toCharArray() ;
System.out.println("The Key is " + key) ;
//The message that is being incrypted it being stored into an cArray
char [] messageArray = userMessage.toCharArray() ;
System.out.println("Processing Data...") ;
//This is used to save the message from the user into an external file
PrintWriter writer = new PrintWriter("Message.txt", "UTF-8");
writer.println(userMessage);
writer.close();
//This saves the key into an external file so it can be recorded to encrypt and decrypt the message
PrintWriter kWriter = new PrintWriter("Key.txt", "UTF-8");
kWriter.println(key);
kWriter.close();
szKeyboard.close() ;
findBinary(messageArray , keyArray) ;
}
public static char binaryToChar(String binary)
{
int decimal = Integer.parseInt(binary, 2) ;
return (char) decimal;
}
}
This is a code that I made, on how the Vernam Cipher works and I wanted to have a go for it myself, I wanted to know how I could have made it better and also how to fix my file writing problem where every time I will run this code, the contents within the files would be overwritten. The Vernam Cipher works by taking a Message (userMessage) and applying a key to the message in the form of an XOR Gate. The key in my code is randomly generated and then both of these values are stored into an array. These then get taken to another function and then are converted into binary values, after they have been converted they are stored into another array and then taken to another function that applies the XOR gate to both the key and message (binary values). After this is done the result is stored into another array and is then is converted from Binary to ASCII Text. Please note, I am 16 Years of Age and have only started coding for 5-6 months and do not know much in-depth things yet.
