Program Java untuk Encode Pesan Menggunakan Playfair Cipher

 on Tuesday, July 28, 2015  


Ini adalah program java untuk menerapkan algoritma cipher Playfair. The Playfair cipher adalah teknik enkripsi simetris manual dan merupakan yang pertama dari literal cipher substitusi.

Berikut adalah kode / source code dari program Java untuk Encode Pesan Menggunakan Playfair Cipher. Program Java berhasil dikompilasi dan dijalankan pada sistem Windows dan Linux. Output 
Program ini juga ditunjukkan di bawah.

import java.util.Scanner;
public class PlayfairCipherEncryption
{
    private String KeyWord        = new String();
    private String Key            = new String();
    private char   matrix_arr[][] = new char[5][5];

   public void setKey(String k)
    {
        String K_adjust = new String();
        boolean flag = false;
        K_adjust = K_adjust + k.charAt(0);
        for (int i = 1; i < k.length(); i++)
        {
            for (int j = 0; j < K_adjust.length(); j++)
           {
                if (k.charAt(i) == K_adjust.charAt(j))
                {
                    flag = true;
                }
            }
            if (flag == false)
                K_adjust = K_adjust + k.charAt(i);
            flag = false;
        }
        KeyWord = K_adjust;
    }

    public void KeyGen()
    {
        boolean flag = true;
        char current;
        Key = KeyWord;
        for (int i = 0; i < 26; i++)
        {
            current = (char) (i + 97);
            if (current == 'j')
                continue;
            for (int j = 0; j < KeyWord.length(); j++)
            {
                if (current == KeyWord.charAt(j))
                {
                    flag = false;
                    break;
                }
            }
            if (flag)
                Key = Key + current;
            flag = true;
        }
        System.out.println(Key);
        matrix();
    }

    private void matrix()
    {
        int counter = 0;
        for (int i = 0; i < 5; i++)
        {
            for (int j = 0; j < 5; j++)
            {
                matrix_arr[i][j] = Key.charAt(counter);
                System.out.print(matrix_arr[i][j] + " ");
                counter++;
            }
            System.out.println();
        }
    }

    private String format(String old_text)
    {
        int i = 0;
        int len = 0;
        String text = new String();
        len = old_text.length();
        for (int tmp = 0; tmp < len; tmp++)
        {
            if (old_text.charAt(tmp) == 'j')
          {
                text = text + 'i';
            }
            else
                text = text + old_text.charAt(tmp);
        }
        len = text.length();
        for (i = 0; i < len; i = i + 2)
        {
            if (text.charAt(i + 1) == text.charAt(i))
            {
                text = text.substring(0, i + 1) + 'x' + text.substring(i + 1);
            }
        }
       return text;
    }

    private String[] Divid2Pairs(String new_string)
    {
        String Original = format(new_string);
        int size = Original.length();
        if (size % 2 != 0)
        {
            size++;
            Original = Original + 'x';
        }
        String x[] = new String[size / 2];
        int counter = 0;
        for (int i = 0; i < size / 2; i++)
        {
            x[i] = Original.substring(counter, counter + 2);
            counter = counter + 2;
        }
        return x;
    }
                 
    public int[] GetDiminsions(char letter)
    {
        int[] key = new int[2];
        if (letter == 'j')
            letter = 'i';
        for (int i = 0; i < 5; i++)
       {
            for (int j = 0; j < 5; j++)
            {
                if (matrix_arr[i][j] == letter)
                {
                    key[0] = i;
                    key[1] = j;
                    break;
                }
            }
        }
        return key;
    }

    public String encryptMessage(String Source)
    {
        String src_arr[] = Divid2Pairs(Source);
        String Code = new String();
        char one;
        char two;
        int part1[] = new int[2];
        int part2[] = new int[2];
        for (int i = 0; i < src_arr.length; i++)
        {
          one = src_arr[i].charAt(0);
            two = src_arr[i].charAt(1);
            part1 = GetDiminsions(one);
            part2 = GetDiminsions(two);
            if (part1[0] == part2[0])
            {
                if (part1[1] < 4)
                    part1[1]++;
                else
                    part1[1] = 0;
                if (part2[1] < 4)
                    part2[1]++;
                else
                   part2[1] = 0;
           }
           else if (part1[1] == part2[1])
            {
                if (part1[0] < 4)
                    part1[0]++;
                else
                    part1[0] = 0;
                if (part2[0] < 4)
                    part2[0]++;
                else
                    part2[0] = 0;
            }
            else
            {
                int temp = part1[1];
                part1[1] = part2[1];
                part2[1] = temp;
            }
            Code = Code + matrix_arr[part1[0]][part1[1]]
                   + matrix_arr[part2[0]][part2[1]];
        }
        return Code;
    }

   public static void main(String[] args)
    {
        PlayfairCipherEncryption x = new PlayfairCipherEncryption();
        Scanner sc = new Scanner(System.in);
        System.out.println("Enter a keyword:");
        String keyword = sc.next();
        x.setKey(keyword);
        x.KeyGen();
        System.out
                .println("Enter word to encrypt: (Make sure length of message is even)");
        String key_input = sc.next();
        if (key_input.length() % 2 == 0)
       {
           System.out.println("Encryption: " + x.encryptMessage(key_input));
        }
        else
       {
           System.out.println("Message length should be even");
        }
        sc.close();
    }
}


Output:
$ javac PlayfairCipherEncryption.java
$ java PlayfairCipherEncryption

Enter a keyword:
Sanfoundry
Sanfoudrybceghiklmpqstvwxz
S a n f o
u d r y b
c e g h i
k l m p q
s t v w x
Enter word to encrypt: (Make sure length of message is even)
Learningcenter

Encryption: acndogrmegavgd

Program Java untuk Encode Pesan Menggunakan Playfair Cipher 4.5 5 Agustinus Darto Iwan Setiawan Tuesday, July 28, 2015 Artikel Indo, Java, Kriptografi, Open Source, Pemrograman, Substitusi, Playfair, Cipher, Enkripsi Ini adalah program java untuk menerapkan algoritma cipher Playfair. The Playfair cipher adalah teknik enkripsi simetris manual dan merupa...


2 comments:

  1. Artikelnya bermanfaat kak, ini saya juga punya artikel tentang Algoritma Playfair Cipher (Lengkap dengan Penjelasan dan Contoh), smoga dpt saling melengkapi

    http://lmgtfy.com/?q=playfair+cipher+markijar

    ReplyDelete
    Replies
    1. Makasih mbak, segera meluncur kesana. Kita kolaborasikan saja mbak

      Delete

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