Update some classes in Ciphers package

Ciphers/AESEncryption.java

@@ -1,13 +1,8 @@
 package Ciphers;
 
+import javax.crypto.*;
 import java.security.InvalidKeyException;
 import java.security.NoSuchAlgorithmException;
-import javax.crypto.BadPaddingException;
-import javax.crypto.Cipher;
-import javax.crypto.IllegalBlockSizeException;
-import javax.crypto.KeyGenerator;
-import javax.crypto.NoSuchPaddingException;
-import javax.crypto.SecretKey;
 
 /**
  * This example program shows how AES encryption and decryption can be done in Java. Please note
@@ -16,82 +11,83 @@ import javax.crypto.SecretKey;
  */
 public class AESEncryption {
 
-  private static final char[] HEX_ARRAY = "0123456789ABCDEF".toCharArray();
-  /**
-   * 1. Generate a plain text for encryption 2. Get a secret key (printed in hexadecimal form). In
-   * actual use this must by encrypted and kept safe. The same key is required for decryption.
-   */
-  public static void main(String[] args) throws Exception {
-    String plainText = "Hello World";
-    SecretKey secKey = getSecretEncryptionKey();
-    byte[] cipherText = encryptText(plainText, secKey);
-    String decryptedText = decryptText(cipherText, secKey);
+    private static final char[] HEX_ARRAY = "0123456789ABCDEF".toCharArray();
 
-    System.out.println("Original Text:" + plainText);
-    System.out.println("AES Key (Hex Form):" + bytesToHex(secKey.getEncoded()));
-    System.out.println("Encrypted Text (Hex Form):" + bytesToHex(cipherText));
-    System.out.println("Descrypted Text:" + decryptedText);
-  }
+    /**
+     * 1. Generate a plain text for encryption 2. Get a secret key (printed in hexadecimal form). In
+     * actual use this must by encrypted and kept safe. The same key is required for decryption.
+     */
+    public static void main(String[] args) throws Exception {
+        String plainText = "Hello World";
+        SecretKey secKey = getSecretEncryptionKey();
+        byte[] cipherText = encryptText(plainText, secKey);
+        String decryptedText = decryptText(cipherText, secKey);
 
-  /**
-   * gets the AES encryption key. In your actual programs, this should be safely stored.
-   *
-   * @return secKey (Secret key that we encrypt using it)
-   * @throws NoSuchAlgorithmException (from KeyGenrator)
-   */
-  public static SecretKey getSecretEncryptionKey() throws NoSuchAlgorithmException {
-    KeyGenerator aesKeyGenerator = KeyGenerator.getInstance("AES");
-    aesKeyGenerator.init(128); // The AES key size in number of bits
-    return aesKeyGenerator.generateKey();
-  }
-
-  /**
-   * Encrypts plainText in AES using the secret key
-   *
-   * @return byteCipherText (The encrypted text)
-   * @throws NoSuchPaddingException (from Cipher)
-   * @throws NoSuchAlgorithmException (from Cipher)
-   * @throws InvalidKeyException (from Cipher)
-   * @throws BadPaddingException (from Cipher)
-   * @throws IllegalBlockSizeException (from Cipher)
-   */
-  public static byte[] encryptText(String plainText, SecretKey secKey)
-      throws NoSuchAlgorithmException, NoSuchPaddingException, InvalidKeyException,
-          IllegalBlockSizeException, BadPaddingException {
-    // AES defaults to AES/ECB/PKCS5Padding in Java 7
-    Cipher aesCipher = Cipher.getInstance("AES");
-    aesCipher.init(Cipher.ENCRYPT_MODE, secKey);
-    return aesCipher.doFinal(plainText.getBytes());
-  }
-
-  /**
-   * Decrypts encrypted byte array using the key used for encryption.
-   *
-   * @return plainText
-   */
-  public static String decryptText(byte[] byteCipherText, SecretKey secKey)
-      throws NoSuchAlgorithmException, NoSuchPaddingException, InvalidKeyException,
-          IllegalBlockSizeException, BadPaddingException {
-    // AES defaults to AES/ECB/PKCS5Padding in Java 7
-    Cipher aesCipher = Cipher.getInstance("AES");
-    aesCipher.init(Cipher.DECRYPT_MODE, secKey);
-    byte[] bytePlainText = aesCipher.doFinal(byteCipherText);
-    return new String(bytePlainText);
-  }
-
-  /**
-   * Convert a binary byte array into readable hex form Old library is deprecated on OpenJdk 11 and
-   * this is faster regarding other solution is using StringBuilder
-   *
-   * @return hexHash
-   */
-  public static String bytesToHex(byte[] bytes) {
-    char[] hexChars = new char[bytes.length * 2];
-    for (int j = 0; j < bytes.length; j++) {
-      int v = bytes[j] & 0xFF;
-      hexChars[j * 2] = HEX_ARRAY[v >>> 4];
-      hexChars[j * 2 + 1] = HEX_ARRAY[v & 0x0F];
+        System.out.println("Original Text:" + plainText);
+        System.out.println("AES Key (Hex Form):" + bytesToHex(secKey.getEncoded()));
+        System.out.println("Encrypted Text (Hex Form):" + bytesToHex(cipherText));
+        System.out.println("Descrypted Text:" + decryptedText);
+    }
+
+    /**
+     * gets the AES encryption key. In your actual programs, this should be safely stored.
+     *
+     * @return secKey (Secret key that we encrypt using it)
+     * @throws NoSuchAlgorithmException (from KeyGenrator)
+     */
+    public static SecretKey getSecretEncryptionKey() throws NoSuchAlgorithmException {
+        KeyGenerator aesKeyGenerator = KeyGenerator.getInstance("AES");
+        aesKeyGenerator.init(128); // The AES key size in number of bits
+        return aesKeyGenerator.generateKey();
+    }
+
+    /**
+     * Encrypts plainText in AES using the secret key
+     *
+     * @return byteCipherText (The encrypted text)
+     * @throws NoSuchPaddingException    (from Cipher)
+     * @throws NoSuchAlgorithmException  (from Cipher)
+     * @throws InvalidKeyException       (from Cipher)
+     * @throws BadPaddingException       (from Cipher)
+     * @throws IllegalBlockSizeException (from Cipher)
+     */
+    public static byte[] encryptText(String plainText, SecretKey secKey)
+            throws NoSuchAlgorithmException, NoSuchPaddingException, InvalidKeyException,
+            IllegalBlockSizeException, BadPaddingException {
+        // AES defaults to AES/ECB/PKCS5Padding in Java 7
+        Cipher aesCipher = Cipher.getInstance("AES");
+        aesCipher.init(Cipher.ENCRYPT_MODE, secKey);
+        return aesCipher.doFinal(plainText.getBytes());
+    }
+
+    /**
+     * Decrypts encrypted byte array using the key used for encryption.
+     *
+     * @return plainText
+     */
+    public static String decryptText(byte[] byteCipherText, SecretKey secKey)
+            throws NoSuchAlgorithmException, NoSuchPaddingException, InvalidKeyException,
+            IllegalBlockSizeException, BadPaddingException {
+        // AES defaults to AES/ECB/PKCS5Padding in Java 7
+        Cipher aesCipher = Cipher.getInstance("AES");
+        aesCipher.init(Cipher.DECRYPT_MODE, secKey);
+        byte[] bytePlainText = aesCipher.doFinal(byteCipherText);
+        return new String(bytePlainText);
+    }
+
+    /**
+     * Convert a binary byte array into readable hex form Old library is deprecated on OpenJdk 11 and
+     * this is faster regarding other solution is using StringBuilder
+     *
+     * @return hexHash
+     */
+    public static String bytesToHex(byte[] bytes) {
+        char[] hexChars = new char[bytes.length * 2];
+        for (int j = 0; j < bytes.length; j++) {
+            int v = bytes[j] & 0xFF;
+            hexChars[j * 2] = HEX_ARRAY[v >>> 4];
+            hexChars[j * 2 + 1] = HEX_ARRAY[v & 0x0F];
+        }
+        return new String(hexChars);
     }
-    return new String(hexChars);
-  }
 }

Ciphers/AffineCipher.java

@@ -1,36 +1,23 @@
-//The ‘key’ for the Affine cipher consists of 2 numbers, we’ll call them a and b.
-// The following discussion assumes the use of a 26 character alphabet (m = 26).
-// a should be chosen to be relatively prime to m (i.e. a should have no factors in common with m).
-
 package Ciphers;
 
-import java.util.Scanner;
+class AffineCipher {
 
-class AffineCipher
-{
-    static Scanner in = new Scanner(System.in);
+    // Key values of a and b
+    static int a = 17;
+    static int b = 20;
 
-    static String encryptMessage(char[] msg)
-    {
-        System.out.println("Enter key value a for encryption : ");
-        int a = in.nextInt();
-        
-        System.out.println("Enter key value b for encryption : ");
-        int b = in.nextInt();
-        
-        /// Initially empty cipher String
+    static String encryptMessage(char[] msg) {
+        /// Cipher Text initially empty
         String cipher = "";
-        for (int i = 0; i < msg.length; i++)
-        {
+        for (int i = 0; i < msg.length; i++) {
             // Avoid space to be encrypted
             /* applying encryption formula ( a x + b ) mod m
             {here x is msg[i] and m is 26} and added 'A' to
             bring it in range of ascii alphabet[ 65-90 | A-Z ] */
-            if (msg[i] != ' ')
-            {
+            if (msg[i] != ' ') {
                 cipher = cipher
                         + (char) ((((a * (msg[i] - 'A')) + b) % 26) + 'A');
-            } else // append space character
+            } else // else simply append space character
             {
                 cipher += msg[i];
             }
@@ -38,42 +25,30 @@ class AffineCipher
         return cipher;
     }
 
-    static String decryptCipher(String cipher)
-    {
-        System.out.println("Enter key value a for decryption : ");
-        int a = in.nextInt();
-        
-        System.out.println("Enter key value b for decryption : ");
-        int b = in.nextInt();
-        
+    static String decryptCipher(String cipher) {
         String msg = "";
         int a_inv = 0;
         int flag = 0;
 
         //Find a^-1 (the multiplicative inverse of a
         //in the group of integers modulo m.)
-        for (int i = 0; i < 26; i++)
-        {
+        for (int i = 0; i < 26; i++) {
             flag = (a * i) % 26;
 
             // Check if (a*i)%26 == 1,
-            // if so, then i will be the multiplicative inverse of a
-            if (flag == 1)
-            {
+            // then i will be the multiplicative inverse of a
+            if (flag == 1) {
                 a_inv = i;
             }
         }
-        for (int i = 0; i < cipher.length(); i++)
-        {
+        for (int i = 0; i < cipher.length(); i++) {
             /*Applying decryption formula a^-1 ( x - b ) mod m
             {here x is cipher[i] and m is 26} and added 'A'
             to bring it in range of ASCII alphabet[ 65-90 | A-Z ] */
-            if (cipher.charAt(i) != ' ')
-            {
+            if (cipher.charAt(i) != ' ') {
                 msg = msg + (char) (((a_inv *
                         ((cipher.charAt(i) + 'A' - b)) % 26)) + 'A');
-            }
-            else // append space character
+            } else //else simply append space character
             {
                 msg += cipher.charAt(i);
             }
@@ -82,17 +57,17 @@ class AffineCipher
         return msg;
     }
 
-    // Main method
-    public static void main(String[] args)
-    {
+    // Driver code
+    public static void main(String[] args) {
         String msg = "AFFINE CIPHER";
 
-        // Encrypting message
+        // Calling encryption function
         String cipherText = encryptMessage(msg.toCharArray());
         System.out.println("Encrypted Message is : " + cipherText);
 
-        // Decrypting message
+        // Calling Decryption function
         System.out.println("Decrypted Message is: " + decryptCipher(cipherText));
 
     }
 }
+

Ciphers/Caesar.java

@@ -11,105 +11,105 @@ import java.util.Scanner;
  */
 public class Caesar {
 
-  /**
-   * Encrypt text by shifting every Latin char by add number shift for ASCII Example : A + 1 -> B
-   *
-   * @return Encrypted message
-   */
-  public static String encode(String message, int shift) {
-    StringBuilder encoded = new StringBuilder();
+    /**
+     * Encrypt text by shifting every Latin char by add number shift for ASCII Example : A + 1 -> B
+     *
+     * @return Encrypted message
+     */
+    public static String encode(String message, int shift) {
+        StringBuilder encoded = new StringBuilder();
 
-    shift %= 26;
+        shift %= 26;
 
-    final int length = message.length();
-    for (int i = 0; i < length; i++) {
+        final int length = message.length();
+        for (int i = 0; i < length; i++) {
 
-      //            int current = message.charAt(i); //using char to shift characters because ascii
-      // is in-order latin alphabet
-      char current = message.charAt(i); // Java law : char + int = char
+            //            int current = message.charAt(i); //using char to shift characters because ascii
+            // is in-order latin alphabet
+            char current = message.charAt(i); // Java law : char + int = char
 
-      if (IsCapitalLatinLetter(current)) {
+            if (IsCapitalLatinLetter(current)) {
 
-        current += shift;
-        encoded.append((char) (current > 'Z' ? current - 26 : current)); // 26 = number of latin letters
+                current += shift;
+                encoded.append((char) (current > 'Z' ? current - 26 : current)); // 26 = number of latin letters
 
-      } else if (IsSmallLatinLetter(current)) {
+            } else if (IsSmallLatinLetter(current)) {
 
-        current += shift;
-        encoded.append((char) (current > 'z' ? current - 26 : current)); // 26 = number of latin letters
+                current += shift;
+                encoded.append((char) (current > 'z' ? current - 26 : current)); // 26 = number of latin letters
 
-      } else {
-        encoded.append(current);
-      }
+            } else {
+                encoded.append(current);
+            }
+        }
+        return encoded.toString();
     }
-    return encoded.toString();
-  }
 
-  /**
-   * Decrypt message by shifting back every Latin char to previous the ASCII Example : B - 1 -> A
-   *
-   * @return message
-   */
-  public static String decode(String encryptedMessage, int shift) {
-    StringBuilder decoded = new StringBuilder();
+    /**
+     * Decrypt message by shifting back every Latin char to previous the ASCII Example : B - 1 -> A
+     *
+     * @return message
+     */
+    public static String decode(String encryptedMessage, int shift) {
+        StringBuilder decoded = new StringBuilder();
 
-    shift %= 26;
+        shift %= 26;
 
-    final int length = encryptedMessage.length();
-    for (int i = 0; i < length; i++) {
-      char current = encryptedMessage.charAt(i);
-      if (IsCapitalLatinLetter(current)) {
+        final int length = encryptedMessage.length();
+        for (int i = 0; i < length; i++) {
+            char current = encryptedMessage.charAt(i);
+            if (IsCapitalLatinLetter(current)) {
 
-        current -= shift;
-        decoded.append((char) (current < 'A' ? current + 26 : current)); // 26 = number of latin letters
+                current -= shift;
+                decoded.append((char) (current < 'A' ? current + 26 : current)); // 26 = number of latin letters
 
-      } else if (IsSmallLatinLetter(current)) {
+            } else if (IsSmallLatinLetter(current)) {
 
-        current -= shift;
-        decoded.append((char) (current < 'a' ? current + 26 : current)); // 26 = number of latin letters
+                current -= shift;
+                decoded.append((char) (current < 'a' ? current + 26 : current)); // 26 = number of latin letters
 
-      } else {
-        decoded.append(current);
-      }
+            } else {
+                decoded.append(current);
+            }
+        }
+        return decoded.toString();
     }
-    return decoded.toString();
-  }
 
-  /**
-   * @return true if character is capital Latin letter or false for others
-   */
-  private static boolean IsCapitalLatinLetter(char c) {
-    return c >= 'A' && c <= 'Z';
-  }
-
-  /**
-   * @return true if character is small Latin letter or false for others
-   */
-  private static boolean IsSmallLatinLetter(char c) {
-    return c >= 'a' && c <= 'z';
-  }
-
-  public static void main(String[] args) {
-    Scanner input = new Scanner(System.in);
-    System.out.println("Please enter the message (Latin Alphabet)");
-    String message = input.nextLine();
-    System.out.println(message);
-    System.out.println("Please enter the shift number");
-    int shift = input.nextInt() % 26;
-    System.out.println("(E)ncode or (D)ecode ?");
-    char choice = input.next().charAt(0);
-    switch (choice) {
-      case 'E':
-      case 'e':
-        System.out.println(
-            "ENCODED MESSAGE IS \n" + encode(message, shift)); // send our function to handle
-        break;
-      case 'D':
-      case 'd':
-        System.out.println("DECODED MESSAGE IS \n" + decode(message, shift));
-      default:
-        System.out.println("default case");
+    /**
+     * @return true if character is capital Latin letter or false for others
+     */
+    private static boolean IsCapitalLatinLetter(char c) {
+        return c >= 'A' && c <= 'Z';
+    }
+
+    /**
+     * @return true if character is small Latin letter or false for others
+     */
+    private static boolean IsSmallLatinLetter(char c) {
+        return c >= 'a' && c <= 'z';
+    }
+
+    public static void main(String[] args) {
+        Scanner input = new Scanner(System.in);
+        System.out.println("Please enter the message (Latin Alphabet)");
+        String message = input.nextLine();
+        System.out.println(message);
+        System.out.println("Please enter the shift number");
+        int shift = input.nextInt() % 26;
+        System.out.println("(E)ncode or (D)ecode ?");
+        char choice = input.next().charAt(0);
+        switch (choice) {
+            case 'E':
+            case 'e':
+                System.out.println(
+                        "ENCODED MESSAGE IS \n" + encode(message, shift)); // send our function to handle
+                break;
+            case 'D':
+            case 'd':
+                System.out.println("DECODED MESSAGE IS \n" + decode(message, shift));
+            default:
+                System.out.println("default case");
+        }
+        input.close();
     }
-    input.close();
-  }
 }

Ciphers/ColumnarTranspositionCipher.java

@@ -9,191 +9,193 @@ import java.util.Objects;
  */
 public class ColumnarTranspositionCipher {
 
-  private static String keyword;
-  private static Object[][] table;
-  private static String abecedarium;
-  public static final String ABECEDARIUM =
-      "abcdefghijklmnopqrstuvwxyzABCDEFG" + "HIJKLMNOPQRSTUVWXYZ0123456789,.;:-@";
-  private static final String ENCRYPTION_FIELD = "≈";
-  private static final char ENCRYPTION_FIELD_CHAR = '≈';
+    private static String keyword;
+    private static Object[][] table;
+    private static String abecedarium;
+    public static final String ABECEDARIUM =
+            "abcdefghijklmnopqrstuvwxyzABCDEFG" + "HIJKLMNOPQRSTUVWXYZ0123456789,.;:-@";
+    private static final String ENCRYPTION_FIELD = "≈";
+    private static final char ENCRYPTION_FIELD_CHAR = '≈';
 
-  /**
-   * Encrypts a certain String with the Columnar Transposition Cipher Rule
-   *
-   * @param word Word being encrypted
-   * @param keyword String with keyword being used
-   * @return a String with the word encrypted by the Columnar Transposition Cipher Rule
-   */
-  public static String encrpyter(String word, String keyword) {
-    ColumnarTranspositionCipher.keyword = keyword;
-    abecedariumBuilder(500);
-    table = tableBuilder(word);
-    Object[][] sortedTable = sortTable(table);
-    StringBuilder wordEncrypted = new StringBuilder();
-    for (int i = 0; i < sortedTable[i].length; i++) {
-      for (int j = 1; j < sortedTable.length; j++) {
-        wordEncrypted.append(sortedTable[j][i]);
-      }
+    /**
+     * Encrypts a certain String with the Columnar Transposition Cipher Rule
+     *
+     * @param word    Word being encrypted
+     * @param keyword String with keyword being used
+     * @return a String with the word encrypted by the Columnar Transposition Cipher Rule
+     */
+    public static String encrpyter(String word, String keyword) {
+        ColumnarTranspositionCipher.keyword = keyword;
+        abecedariumBuilder(500);
+        table = tableBuilder(word);
+        Object[][] sortedTable = sortTable(table);
+        StringBuilder wordEncrypted = new StringBuilder();
+        for (int i = 0; i < sortedTable[i].length; i++) {
+            for (int j = 1; j < sortedTable.length; j++) {
+                wordEncrypted.append(sortedTable[j][i]);
+            }
+        }
+        return wordEncrypted.toString();
     }
-    return wordEncrypted.toString();
-  }
 
-  /**
-   * Encrypts a certain String with the Columnar Transposition Cipher Rule
-   *
-   * @param word Word being encrypted
-   * @param keyword String with keyword being used
-   * @param abecedarium String with the abecedarium being used. null for default one
-   * @return a String with the word encrypted by the Columnar Transposition Cipher Rule
-   */
-  public static String encrpyter(String word, String keyword, String abecedarium) {
-    ColumnarTranspositionCipher.keyword = keyword;
-    ColumnarTranspositionCipher.abecedarium = Objects.requireNonNullElse(abecedarium, ABECEDARIUM);
-    table = tableBuilder(word);
-    Object[][] sortedTable = sortTable(table);
-    StringBuilder wordEncrypted = new StringBuilder();
-    for (int i = 0; i < sortedTable[0].length; i++) {
-      for (int j = 1; j < sortedTable.length; j++) {
-        wordEncrypted.append(sortedTable[j][i]);
-      }
+    /**
+     * Encrypts a certain String with the Columnar Transposition Cipher Rule
+     *
+     * @param word        Word being encrypted
+     * @param keyword     String with keyword being used
+     * @param abecedarium String with the abecedarium being used. null for default one
+     * @return a String with the word encrypted by the Columnar Transposition Cipher Rule
+     */
+    public static String encrpyter(String word, String keyword, String abecedarium) {
+        ColumnarTranspositionCipher.keyword = keyword;
+        ColumnarTranspositionCipher.abecedarium = Objects.requireNonNullElse(abecedarium, ABECEDARIUM);
+        table = tableBuilder(word);
+        Object[][] sortedTable = sortTable(table);
+        StringBuilder wordEncrypted = new StringBuilder();
+        for (int i = 0; i < sortedTable[0].length; i++) {
+            for (int j = 1; j < sortedTable.length; j++) {
+                wordEncrypted.append(sortedTable[j][i]);
+            }
+        }
+        return wordEncrypted.toString();
     }
-    return wordEncrypted.toString();
-  }
 
-  /**
-   * Decrypts a certain encrypted String with the Columnar Transposition Cipher Rule
-   *
-   * @return a String decrypted with the word encrypted by the Columnar Transposition Cipher Rule
-   */
-  public static String decrypter() {
-    StringBuilder wordDecrypted = new StringBuilder();
-    for (int i = 1; i < table.length; i++) {
-      for (Object item : table[i]) {
-        wordDecrypted.append(item);
-      }
+    /**
+     * Decrypts a certain encrypted String with the Columnar Transposition Cipher Rule
+     *
+     * @return a String decrypted with the word encrypted by the Columnar Transposition Cipher Rule
+     */
+    public static String decrypter() {
+        StringBuilder wordDecrypted = new StringBuilder();
+        for (int i = 1; i < table.length; i++) {
+            for (Object item : table[i]) {
+                wordDecrypted.append(item);
+            }
+        }
+        return wordDecrypted.toString().replaceAll(ENCRYPTION_FIELD, "");
     }
-    return wordDecrypted.toString().replaceAll(ENCRYPTION_FIELD, "");
-  }
 
-  /**
-   * Builds a table with the word to be encrypted in rows by the Columnar Transposition Cipher Rule
-   *
-   * @return An Object[][] with the word to be encrypted filled in rows and columns
-   */
-  private static Object[][] tableBuilder(String word) {
-    Object[][] table = new Object[numberOfRows(word) + 1][keyword.length()];
-    char[] wordInChards = word.toCharArray();
-    // Fils in the respective numbers
-    table[0] = findElements();
-    int charElement = 0;
-    for (int i = 1; i < table.length; i++) {
-      for (int j = 0; j < table[i].length; j++) {
-        if (charElement < wordInChards.length) {
-          table[i][j] = wordInChards[charElement];
-          charElement++;
+    /**
+     * Builds a table with the word to be encrypted in rows by the Columnar Transposition Cipher Rule
+     *
+     * @return An Object[][] with the word to be encrypted filled in rows and columns
+     */
+    private static Object[][] tableBuilder(String word) {
+        Object[][] table = new Object[numberOfRows(word) + 1][keyword.length()];
+        char[] wordInChards = word.toCharArray();
+        // Fils in the respective numbers
+        table[0] = findElements();
+        int charElement = 0;
+        for (int i = 1; i < table.length; i++) {
+            for (int j = 0; j < table[i].length; j++) {
+                if (charElement < wordInChards.length) {
+                    table[i][j] = wordInChards[charElement];
+                    charElement++;
+                } else {
+                    table[i][j] = ENCRYPTION_FIELD_CHAR;
+                }
+            }
+        }
+        return table;
+    }
+
+    /**
+     * Determines the number of rows the table should have regarding the Columnar Transposition Cipher
+     * Rule
+     *
+     * @return an int with the number of rows that the table should have in order to respect the
+     * Columnar Transposition Cipher Rule.
+     */
+    private static int numberOfRows(String word) {
+        if (word.length() / keyword.length() > word.length() / keyword.length()) {
+            return (word.length() / keyword.length()) + 1;
         } else {
-          table[i][j] = ENCRYPTION_FIELD_CHAR;
+            return word.length() / keyword.length();
         }
-      }
     }
-    return table;
-  }
 
-  /**
-   * Determines the number of rows the table should have regarding the Columnar Transposition Cipher
-   * Rule
-   *
-   * @return an int with the number of rows that the table should have in order to respect the
-   *     Columnar Transposition Cipher Rule.
-   */
-  private static int numberOfRows(String word) {
-    if (word.length() / keyword.length() > word.length() / keyword.length()) {
-      return (word.length() / keyword.length()) + 1;
-    } else {
-      return word.length() / keyword.length();
-    }
-  }
-
-  /** @return charValues */
-  private static Object[] findElements() {
-    Object[] charValues = new Object[keyword.length()];
-    for (int i = 0; i < charValues.length; i++) {
-      int charValueIndex = abecedarium.indexOf(keyword.charAt(i));
-      charValues[i] = charValueIndex > -1 ? charValueIndex : null;
-    }
-    return charValues;
-  }
-
-  /**
-   * @return tableSorted
-   */
-  private static Object[][] sortTable(Object[][] table) {
-    Object[][] tableSorted = new Object[table.length][table[0].length];
-    for (int i = 0; i < tableSorted.length; i++) {
-      System.arraycopy(table[i], 0, tableSorted[i], 0, tableSorted[i].length);
-    }
-    for (int i = 0; i < tableSorted[0].length; i++) {
-      for (int j = i + 1; j < tableSorted[0].length; j++) {
-        if ((int) tableSorted[0][i] > (int) table[0][j]) {
-          Object[] column = getColumn(tableSorted, tableSorted.length, i);
-          switchColumns(tableSorted, j, i, column);
+    /**
+     * @return charValues
+     */
+    private static Object[] findElements() {
+        Object[] charValues = new Object[keyword.length()];
+        for (int i = 0; i < charValues.length; i++) {
+            int charValueIndex = abecedarium.indexOf(keyword.charAt(i));
+            charValues[i] = charValueIndex > -1 ? charValueIndex : null;
         }
-      }
+        return charValues;
     }
-    return tableSorted;
-  }
 
-  /**
-   * @return columnArray
-   */
-  private static Object[] getColumn(Object[][] table, int rows, int column) {
-    Object[] columnArray = new Object[rows];
-    for (int i = 0; i < rows; i++) {
-      columnArray[i] = table[i][column];
+    /**
+     * @return tableSorted
+     */
+    private static Object[][] sortTable(Object[][] table) {
+        Object[][] tableSorted = new Object[table.length][table[0].length];
+        for (int i = 0; i < tableSorted.length; i++) {
+            System.arraycopy(table[i], 0, tableSorted[i], 0, tableSorted[i].length);
+        }
+        for (int i = 0; i < tableSorted[0].length; i++) {
+            for (int j = i + 1; j < tableSorted[0].length; j++) {
+                if ((int) tableSorted[0][i] > (int) table[0][j]) {
+                    Object[] column = getColumn(tableSorted, tableSorted.length, i);
+                    switchColumns(tableSorted, j, i, column);
+                }
+            }
+        }
+        return tableSorted;
     }
-    return columnArray;
-  }
 
-  private static void switchColumns(
-      Object[][] table, int firstColumnIndex, int secondColumnIndex, Object[] columnToSwitch) {
-    for (int i = 0; i < table.length; i++) {
-      table[i][secondColumnIndex] = table[i][firstColumnIndex];
-      table[i][firstColumnIndex] = columnToSwitch[i];
+    /**
+     * @return columnArray
+     */
+    private static Object[] getColumn(Object[][] table, int rows, int column) {
+        Object[] columnArray = new Object[rows];
+        for (int i = 0; i < rows; i++) {
+            columnArray[i] = table[i][column];
+        }
+        return columnArray;
     }
-  }
 
-  /**
-   * Creates an abecedarium with a specified ascii inded
-   *
-   * @param value Number of characters being used based on the ASCII Table
-   */
-  private static void abecedariumBuilder(int value) {
-    StringBuilder t = new StringBuilder();
-    for (int i = 0; i < value; i++) {
-      t.append((char) i);
+    private static void switchColumns(
+            Object[][] table, int firstColumnIndex, int secondColumnIndex, Object[] columnToSwitch) {
+        for (int i = 0; i < table.length; i++) {
+            table[i][secondColumnIndex] = table[i][firstColumnIndex];
+            table[i][firstColumnIndex] = columnToSwitch[i];
+        }
     }
-    abecedarium = t.toString();
-  }
 
-  private static void showTable() {
-    for (Object[] table1 : table) {
-      for (Object item : table1) {
-        System.out.print(item + " ");
-      }
-      System.out.println();
+    /**
+     * Creates an abecedarium with a specified ascii inded
+     *
+     * @param value Number of characters being used based on the ASCII Table
+     */
+    private static void abecedariumBuilder(int value) {
+        StringBuilder t = new StringBuilder();
+        for (int i = 0; i < value; i++) {
+            t.append((char) i);
+        }
+        abecedarium = t.toString();
     }
-  }
 
-  public static void main(String[] args) {
-    String keywordForExample = "asd215";
-    String wordBeingEncrypted = "This is a test of the Columnar Transposition Cipher";
-    System.out.println("### Example of Columnar Transposition Cipher ###\n");
-    System.out.println("Word being encryped ->>> " + wordBeingEncrypted);
-    System.out.println(
-        "Word encrypted ->>> "
-            + ColumnarTranspositionCipher.encrpyter(wordBeingEncrypted, keywordForExample));
-    System.out.println("Word decryped ->>> " + ColumnarTranspositionCipher.decrypter());
-    System.out.println("\n### Encrypted Table ###");
-    showTable();
-  }
+    private static void showTable() {
+        for (Object[] table1 : table) {
+            for (Object item : table1) {
+                System.out.print(item + " ");
+            }
+            System.out.println();
+        }
+    }
+
+    public static void main(String[] args) {
+        String keywordForExample = "asd215";
+        String wordBeingEncrypted = "This is a test of the Columnar Transposition Cipher";
+        System.out.println("### Example of Columnar Transposition Cipher ###\n");
+        System.out.println("Word being encryped ->>> " + wordBeingEncrypted);
+        System.out.println(
+                "Word encrypted ->>> "
+                        + ColumnarTranspositionCipher.encrpyter(wordBeingEncrypted, keywordForExample));
+        System.out.println("Word decryped ->>> " + ColumnarTranspositionCipher.decrypter());
+        System.out.println("\n### Encrypted Table ###");
+        showTable();
+    }
 }

Ciphers/HillCipher.java

@@ -1,172 +1,165 @@
 package Ciphers;
 
-import java.util.*;
+import java.util.Scanner;
 
 /*
-* Java Implementation of Hill Cipher
-* Hill cipher is a polyalphabetic substitution cipher. Each letter is represented by a number belonging to the set Z26 where A=0 , B=1, ..... Z=25.
-* To encrypt a message, each block of n letters (since matrix size is n x n) is multiplied by an invertible n × n matrix, against modulus 26.
-* To decrypt the message, each block is multiplied by the inverse of the matrix used for encryption.
-* The cipher key and plaintext/ciphertext are user inputs.
-* @author Ojasva Jain
-*/
+ * Java Implementation of Hill Cipher
+ * Hill cipher is a polyalphabetic substitution cipher. Each letter is represented by a number belonging to the set Z26 where A=0 , B=1, ..... Z=25.
+ * To encrypt a message, each block of n letters (since matrix size is n x n) is multiplied by an invertible n × n matrix, against modulus 26.
+ * To decrypt the message, each block is multiplied by the inverse of the matrix used for encryption.
+ * The cipher key and plaintext/ciphertext are user inputs.
+ * @author Ojasva Jain
+ */
 
-public class HillCipher{
-static Scanner in = new Scanner (System.in);
+public class HillCipher {
+    static Scanner in = new Scanner(System.in);
 
-/* Following function encrypts the message
-*/
-static void encrypt(String message)
-{
-    message = message.toUpperCase();
-    // Get key matrix
-    System.out.println("Enter key matrix size");
-    int n = in.nextInt();
-    System.out.println("Enter Key/encryptionKey matrix ");
-    int keyMatrix[][] = new int [n][n];
-    for(int i=0;i<n;i++){
-        for(int j=0;j<n;j++){
-            keyMatrix[i][j] = in.nextInt();
-        }
-    }
-    //check if det = 0
-    if(determinant(keyMatrix,n)%26 == 0)
-    {
-        System.out.println("Invalid key, as determinant = 0. Program Terminated");
-        return;
-    }
-
-    int [][]messageVector = new int[n][1];
-    String CipherText="";
-    int cipherMatrix [][] = new int [n][1];
-    int j = 0;
-    while(j<message.length()){
-    for (int i = 0; i < n; i++){
-        if(j>=message.length()){ messageVector[i][0] = 23;}
-        else
-        messageVector[i][0] = (message.charAt(j))%65;
-        System.out.println(messageVector[i][0]);
-        j++; 
-    }
-    int x, i;
-    for (i = 0; i < n; i++)
-    {
-        cipherMatrix[i][0] = 0;
-
-            for (x = 0; x < n; x++)
-            {
-                cipherMatrix[i][0] += keyMatrix[i][x] * messageVector[x][0];
+    /* Following function encrypts the message
+     */
+    static void encrypt(String message) {
+        message = message.toUpperCase();
+        // Get key matrix
+        System.out.println("Enter key matrix size");
+        int n = in.nextInt();
+        System.out.println("Enter Key/encryptionKey matrix ");
+        int keyMatrix[][] = new int[n][n];
+        for (int i = 0; i < n; i++) {
+            for (int j = 0; j < n; j++) {
+                keyMatrix[i][j] = in.nextInt();
             }
-            System.out.println(cipherMatrix[i][0]);
-            cipherMatrix[i][0] = cipherMatrix[i][0] % 26;
         }
-    for (i = 0; i < n; i++)
-    CipherText += (char)(cipherMatrix[i][0] + 65);
-}
-System.out.println("Ciphertext: "+ CipherText);
-}
-//Following function decrypts a message
-static void decrypt(String message)
-{
-    message = message.toUpperCase();
-    // Get key matrix
-    System.out.println("Enter key matrix size");
-    int n = in.nextInt();
-    System.out.println("Enter inverseKey/decryptionKey matrix ");
-    int keyMatrix[][] = new int [n][n];
-    for(int i=0;i<n;i++){
-        for(int j=0;j<n;j++){
-            keyMatrix[i][j] = in.nextInt();
+        //check if det = 0
+        if (determinant(keyMatrix, n) % 26 == 0) {
+            System.out.println("Invalid key, as determinant = 0. Program Terminated");
+            return;
         }
-    }
-    //check if det = 0
-    if(determinant(keyMatrix,n)%26 == 0)
-    {
-        System.out.println("Invalid key, as determinant = 0. Program Terminated");
-        return;
-    }
-    //solving for the required plaintext message
-    int [][]messageVector = new int[n][1];
-    String PlainText="";
-    int plainMatrix [][] = new int [n][1];
-    int j = 0;
-    while(j<message.length()){
-        for (int i = 0; i < n; i++){
-            if(j>=message.length()){ messageVector[i][0] = 23;}
-            else
-            messageVector[i][0] = (message.charAt(j))%65;
-            System.out.println(messageVector[i][0]);
-            j++; 
-        }
-        int x, i;
-        for (i = 0; i < n; i++)
-        {
-            plainMatrix[i][0] = 0;
 
-                for (x = 0; x < n; x++)
-                {
+        int[][] messageVector = new int[n][1];
+        String CipherText = "";
+        int cipherMatrix[][] = new int[n][1];
+        int j = 0;
+        while (j < message.length()) {
+            for (int i = 0; i < n; i++) {
+                if (j >= message.length()) {
+                    messageVector[i][0] = 23;
+                } else
+                    messageVector[i][0] = (message.charAt(j)) % 65;
+                System.out.println(messageVector[i][0]);
+                j++;
+            }
+            int x, i;
+            for (i = 0; i < n; i++) {
+                cipherMatrix[i][0] = 0;
+
+                for (x = 0; x < n; x++) {
+                    cipherMatrix[i][0] += keyMatrix[i][x] * messageVector[x][0];
+                }
+                System.out.println(cipherMatrix[i][0]);
+                cipherMatrix[i][0] = cipherMatrix[i][0] % 26;
+            }
+            for (i = 0; i < n; i++)
+                CipherText += (char) (cipherMatrix[i][0] + 65);
+        }
+        System.out.println("Ciphertext: " + CipherText);
+    }
+
+    //Following function decrypts a message
+    static void decrypt(String message) {
+        message = message.toUpperCase();
+        // Get key matrix
+        System.out.println("Enter key matrix size");
+        int n = in.nextInt();
+        System.out.println("Enter inverseKey/decryptionKey matrix ");
+        int keyMatrix[][] = new int[n][n];
+        for (int i = 0; i < n; i++) {
+            for (int j = 0; j < n; j++) {
+                keyMatrix[i][j] = in.nextInt();
+            }
+        }
+        //check if det = 0
+        if (determinant(keyMatrix, n) % 26 == 0) {
+            System.out.println("Invalid key, as determinant = 0. Program Terminated");
+            return;
+        }
+        //solving for the required plaintext message
+        int[][] messageVector = new int[n][1];
+        String PlainText = "";
+        int plainMatrix[][] = new int[n][1];
+        int j = 0;
+        while (j < message.length()) {
+            for (int i = 0; i < n; i++) {
+                if (j >= message.length()) {
+                    messageVector[i][0] = 23;
+                } else
+                    messageVector[i][0] = (message.charAt(j)) % 65;
+                System.out.println(messageVector[i][0]);
+                j++;
+            }
+            int x, i;
+            for (i = 0; i < n; i++) {
+                plainMatrix[i][0] = 0;
+
+                for (x = 0; x < n; x++) {
                     plainMatrix[i][0] += keyMatrix[i][x] * messageVector[x][0];
                 }
 
                 plainMatrix[i][0] = plainMatrix[i][0] % 26;
             }
-        for (i = 0; i < n; i++)
-        PlainText += (char)(plainMatrix[i][0] + 65);
+            for (i = 0; i < n; i++)
+                PlainText += (char) (plainMatrix[i][0] + 65);
+        }
+        System.out.println("Plaintext: " + PlainText);
     }
-    System.out.println("Plaintext: "+PlainText);
-}
 
-// Determinant calculator
-public static int determinant(int a[][], int n){
-    int det = 0, sign = 1, p = 0, q = 0;
+    // Determinant calculator
+    public static int determinant(int a[][], int n) {
+        int det = 0, sign = 1, p = 0, q = 0;
 
-    if(n==1){
-        det = a[0][0];
-    }
-    else{
-        int b[][] = new int[n-1][n-1];
-        for(int x = 0 ; x < n ; x++){
-            p=0;q=0;
-            for(int i = 1;i < n; i++){
-                for(int j = 0; j < n;j++){
-                    if(j != x){
-                        b[p][q++] = a[i][j];
-                        if(q % (n-1) == 0){
-                            p++;
-                            q=0;
+        if (n == 1) {
+            det = a[0][0];
+        } else {
+            int b[][] = new int[n - 1][n - 1];
+            for (int x = 0; x < n; x++) {
+                p = 0;
+                q = 0;
+                for (int i = 1; i < n; i++) {
+                    for (int j = 0; j < n; j++) {
+                        if (j != x) {
+                            b[p][q++] = a[i][j];
+                            if (q % (n - 1) == 0) {
+                                p++;
+                                q = 0;
+                            }
                         }
                     }
                 }
+                det = det + a[0][x] * determinant(b, n - 1) * sign;
+                sign = -sign;
             }
-            det = det + a[0][x] *determinant(b, n-1) * sign;
-            sign = -sign;
         }
+        return det;
     }
-    return det;
-}
 
-// Function to implement Hill Cipher
-static void hillcipher(String message)
-{
-    message.toUpperCase();
-    System.out.println("What do you want to process from the message?");
-    System.out.println("Press 1: To Encrypt");
-    System.out.println("Press 2: To Decrypt");
-    short sc = in.nextShort();
-    if(sc == 1)
-    encrypt(message);
-    else if(sc == 2)
-    decrypt(message);
-    else
-    System.out.println("Invalid input, program terminated.");
-}
+    // Function to implement Hill Cipher
+    static void hillcipher(String message) {
+        message.toUpperCase();
+        System.out.println("What do you want to process from the message?");
+        System.out.println("Press 1: To Encrypt");
+        System.out.println("Press 2: To Decrypt");
+        short sc = in.nextShort();
+        if (sc == 1)
+            encrypt(message);
+        else if (sc == 2)
+            decrypt(message);
+        else
+            System.out.println("Invalid input, program terminated.");
+    }
 
-// Driver code
-public static void main(String[] args)
-   {
-    // Get the message to be encrypted
-    System.out.println("Enter message");
-    String message = in.nextLine();
-    hillcipher(message);
+    // Driver code
+    public static void main(String[] args) {
+        // Get the message to be encrypted
+        System.out.println("Enter message");
+        String message = in.nextLine();
+        hillcipher(message);
     }
 }

Ciphers/RSA.java

@@ -1,74 +1,76 @@
 package Ciphers;
 
+import javax.swing.*;
 import java.math.BigInteger;
 import java.security.SecureRandom;
-import javax.swing.JOptionPane;
 
-/** @author Nguyen Duy Tiep on 23-Oct-17. */
+/**
+ * @author Nguyen Duy Tiep on 23-Oct-17.
+ */
 public final class RSA {
 
-  public static void main(String[] args) {
+    public static void main(String[] args) {
 
-    RSA rsa = new RSA(1024);
-    String text1 = JOptionPane.showInputDialog("Enter a message to encrypt :");
+        RSA rsa = new RSA(1024);
+        String text1 = JOptionPane.showInputDialog("Enter a message to encrypt :");
 
-    String ciphertext = rsa.encrypt(text1);
-    JOptionPane.showMessageDialog(null, "Your encrypted message : " + ciphertext);
+        String ciphertext = rsa.encrypt(text1);
+        JOptionPane.showMessageDialog(null, "Your encrypted message : " + ciphertext);
 
-    JOptionPane.showMessageDialog(null, "Your message after decrypt : " + rsa.decrypt(ciphertext));
-  }
-
-  private BigInteger modulus, privateKey, publicKey;
-
-  public RSA(int bits) {
-    generateKeys(bits);
-  }
-
-  /**
-   * @return encrypted message
-   */
-  public synchronized String encrypt(String message) {
-    return (new BigInteger(message.getBytes())).modPow(publicKey, modulus).toString();
-  }
-
-  /**
-   * @return encrypted message as big integer
-   */
-  public synchronized BigInteger encrypt(BigInteger message) {
-    return message.modPow(publicKey, modulus);
-  }
-
-  /**
-   * @return plain message
-   */
-  public synchronized String decrypt(String encryptedMessage) {
-    return new String((new BigInteger(encryptedMessage)).modPow(privateKey, modulus).toByteArray());
-  }
-
-  /**
-   * @return plain message as big integer
-   */
-  public synchronized BigInteger decrypt(BigInteger encryptedMessage) {
-    return encryptedMessage.modPow(privateKey, modulus);
-  }
-
-  /**
-   * Generate a new public and private key set.
-   */
-  public synchronized void generateKeys(int bits) {
-    SecureRandom r = new SecureRandom();
-    BigInteger p = new BigInteger(bits / 2, 100, r);
-    BigInteger q = new BigInteger(bits / 2, 100, r);
-    modulus = p.multiply(q);
-
-    BigInteger m = (p.subtract(BigInteger.ONE)).multiply(q.subtract(BigInteger.ONE));
-
-    publicKey = new BigInteger("3");
-
-    while (m.gcd(publicKey).intValue() > 1) {
-      publicKey = publicKey.add(new BigInteger("2"));
+        JOptionPane.showMessageDialog(null, "Your message after decrypt : " + rsa.decrypt(ciphertext));
     }
 
-    privateKey = publicKey.modInverse(m);
-  }
+    private BigInteger modulus, privateKey, publicKey;
+
+    public RSA(int bits) {
+        generateKeys(bits);
+    }
+
+    /**
+     * @return encrypted message
+     */
+    public synchronized String encrypt(String message) {
+        return (new BigInteger(message.getBytes())).modPow(publicKey, modulus).toString();
+    }
+
+    /**
+     * @return encrypted message as big integer
+     */
+    public synchronized BigInteger encrypt(BigInteger message) {
+        return message.modPow(publicKey, modulus);
+    }
+
+    /**
+     * @return plain message
+     */
+    public synchronized String decrypt(String encryptedMessage) {
+        return new String((new BigInteger(encryptedMessage)).modPow(privateKey, modulus).toByteArray());
+    }
+
+    /**
+     * @return plain message as big integer
+     */
+    public synchronized BigInteger decrypt(BigInteger encryptedMessage) {
+        return encryptedMessage.modPow(privateKey, modulus);
+    }
+
+    /**
+     * Generate a new public and private key set.
+     */
+    public synchronized void generateKeys(int bits) {
+        SecureRandom r = new SecureRandom();
+        BigInteger p = new BigInteger(bits / 2, 100, r);
+        BigInteger q = new BigInteger(bits / 2, 100, r);
+        modulus = p.multiply(q);
+
+        BigInteger m = (p.subtract(BigInteger.ONE)).multiply(q.subtract(BigInteger.ONE));
+
+        publicKey = new BigInteger("3");
+
+        while (m.gcd(publicKey).intValue() > 1) {
+            publicKey = publicKey.add(new BigInteger("2"));
+        }
+
+        privateKey = publicKey.modInverse(m);
+    }
 }

Ciphers/SimpleSubCipher.java

@@ -1,18 +1,17 @@
 package ciphers;
 
-import java.util.*;
+import java.util.HashMap;
+import java.util.Map;
 
 /**
- *
  * The simple substitution cipher is a cipher that has been in use for many hundreds of years
  * (an excellent history is given in Simon Singhs 'the Code Book').
  * It basically consists of substituting every plaintext character for a different ciphertext character.
  * It differs from the Caesar cipher in that the cipher alphabet is not simply the alphabet shifted,
  * it is completely jumbled.
- * 
  */
 
-public class simpleSubCipher {
+public class SimpleSubCipher {
 
     /**
      * Encrypt text by replacing each element with its opposite character.
@@ -25,7 +24,7 @@ public class simpleSubCipher {
         String encoded = "";
 
         // This map is used to encode
-        Map<Character,Character> cipherMap = new HashMap<Character,Character>();
+        Map<Character, Character> cipherMap = new HashMap<>();
 
         char beginSmallLetter = 'a';
         char beginCapitalLetter = 'A';
@@ -34,13 +33,13 @@ public class simpleSubCipher {
         String cipherCapital = cipherSmall.toUpperCase();
 
         // To handle Small and Capital letters
-        for(int i = 0; i < cipherSmall.length(); i++){
-            cipherMap.put(beginSmallLetter++,cipherSmall.charAt(i));
-            cipherMap.put(beginCapitalLetter++,cipherCapital.charAt(i));
+        for (int i = 0; i < cipherSmall.length(); i++) {
+            cipherMap.put(beginSmallLetter++, cipherSmall.charAt(i));
+            cipherMap.put(beginCapitalLetter++, cipherCapital.charAt(i));
         }
 
-        for(int i = 0; i < message.length(); i++){
-            if(Character.isAlphabetic(message.charAt(i)))
+        for (int i = 0; i < message.length(); i++) {
+            if (Character.isAlphabetic(message.charAt(i)))
                 encoded += cipherMap.get(message.charAt(i));
             else
                 encoded += message.charAt(i);
@@ -60,7 +59,7 @@ public class simpleSubCipher {
         String decoded = "";
 
 
-        Map<Character,Character> cipherMap = new HashMap<Character,Character>();
+        Map<Character, Character> cipherMap = new HashMap<Character, Character>();
 
         char beginSmallLetter = 'a';
         char beginCapitalLetter = 'A';
@@ -68,13 +67,13 @@ public class simpleSubCipher {
         cipherSmall = cipherSmall.toLowerCase();
         String cipherCapital = cipherSmall.toUpperCase();
 
-        for(int i = 0; i < cipherSmall.length(); i++){
-            cipherMap.put(cipherSmall.charAt(i),beginSmallLetter++);
-            cipherMap.put(cipherCapital.charAt(i),beginCapitalLetter++);
+        for (int i = 0; i < cipherSmall.length(); i++) {
+            cipherMap.put(cipherSmall.charAt(i), beginSmallLetter++);
+            cipherMap.put(cipherCapital.charAt(i), beginCapitalLetter++);
         }
 
-        for(int i = 0; i < encryptedMessage.length(); i++){
-            if(Character.isAlphabetic(encryptedMessage.charAt(i)))
+        for (int i = 0; i < encryptedMessage.length(); i++) {
+            if (Character.isAlphabetic(encryptedMessage.charAt(i)))
                 decoded += cipherMap.get(encryptedMessage.charAt(i));
             else
                 decoded += encryptedMessage.charAt(i);
@@ -84,8 +83,8 @@ public class simpleSubCipher {
     }
 
     public static void main(String[] args) {
-        String a = encode("defend the east wall of the castle","phqgiumeaylnofdxjkrcvstzwb");
-        String b = decode(a,"phqgiumeaylnofdxjkrcvstzwb");
+        String a = encode("defend the east wall of the castle", "phqgiumeaylnofdxjkrcvstzwb");
+        String b = decode(a, "phqgiumeaylnofdxjkrcvstzwb");
         System.out.println(b);
     }
 

Ciphers/SimpleSubstitutionCipher.java

@@ -1,6 +1,7 @@
 package Ciphers;
 
-import java.util.*;
+import java.util.HashMap;
+import java.util.Map;
 
 /**
  * The simple substitution cipher is a cipher that has been in use for many hundreds of years (an
@@ -13,71 +14,73 @@ import java.util.*;
  */
 public class SimpleSubstitutionCipher {
 
-  /**
-   * Encrypt text by replacing each element with its opposite character.
-   *
-   * @return Encrypted message
-   */
-  public static String encode(String message, String cipherSmall) {
-    StringBuilder encoded = new StringBuilder();
+    /**
+     * Encrypt text by replacing each element with its opposite character.
+     *
+     * @return Encrypted message
+     */
+    public static String encode(String message, String cipherSmall) {
+        StringBuilder encoded = new StringBuilder();
 
-    // This map is used to encode
-    Map<Character, Character> cipherMap = new HashMap<>();
+        // This map is used to encode
+        Map<Character, Character> cipherMap = new HashMap<>();
 
-    char beginSmallLetter = 'a';
-    char beginCapitalLetter = 'A';
+        char beginSmallLetter = 'a';
+        char beginCapitalLetter = 'A';
 
-    cipherSmall = cipherSmall.toLowerCase();
-    String cipherCapital = cipherSmall.toUpperCase();
+        cipherSmall = cipherSmall.toLowerCase();
+        String cipherCapital = cipherSmall.toUpperCase();
 
-    // To handle Small and Capital letters
-    for (int i = 0; i < cipherSmall.length(); i++) {
-      cipherMap.put(beginSmallLetter++, cipherSmall.charAt(i));
-      cipherMap.put(beginCapitalLetter++, cipherCapital.charAt(i));
+        // To handle Small and Capital letters
+        for (int i = 0; i < cipherSmall.length(); i++) {
+            cipherMap.put(beginSmallLetter++, cipherSmall.charAt(i));
+            cipherMap.put(beginCapitalLetter++, cipherCapital.charAt(i));
+        }
+
+        for (int i = 0; i < message.length(); i++) {
+            if (Character.isAlphabetic(message.charAt(i))) encoded.append(cipherMap.get(message.charAt(i)));
+            else encoded.append(message.charAt(i));
+        }
+
+        return encoded.toString();
     }
 
-    for (int i = 0; i < message.length(); i++) {
-      if (Character.isAlphabetic(message.charAt(i))) encoded.append(cipherMap.get(message.charAt(i)));
-      else encoded.append(message.charAt(i));
+    /**
+     * Decrypt message by replacing each element with its opposite character in cipher.
+     *
+     * @return message
+     */
+    public static String decode(String encryptedMessage, String cipherSmall) {
+        StringBuilder decoded = new StringBuilder();
+
+        Map<Character, Character> cipherMap = new HashMap<>();
+
+        char beginSmallLetter = 'a';
+        char beginCapitalLetter = 'A';
+
+        cipherSmall = cipherSmall.toLowerCase();
+        String cipherCapital = cipherSmall.toUpperCase();
+
+        for (int i = 0; i < cipherSmall.length(); i++) {
+            cipherMap.put(cipherSmall.charAt(i), beginSmallLetter++);
+            cipherMap.put(cipherCapital.charAt(i), beginCapitalLetter++);
+        }
+
+        for (int i = 0; i < encryptedMessage.length(); i++) {
+            if (Character.isAlphabetic(encryptedMessage.charAt(i)))
+                decoded.append(cipherMap.get(encryptedMessage.charAt(i)));
+            else decoded.append(encryptedMessage.charAt(i));
+        }
+
+        return decoded.toString();
     }
 
-    return encoded.toString();
-  }
-
-  /**
-   * Decrypt message by replacing each element with its opposite character in cipher.
-   *
-   * @return message
-   */
-  public static String decode(String encryptedMessage, String cipherSmall) {
-    StringBuilder decoded = new StringBuilder();
-
-    Map<Character, Character> cipherMap = new HashMap<>();
-
-    char beginSmallLetter = 'a';
-    char beginCapitalLetter = 'A';
-
-    cipherSmall = cipherSmall.toLowerCase();
-    String cipherCapital = cipherSmall.toUpperCase();
-
-    for (int i = 0; i < cipherSmall.length(); i++) {
-      cipherMap.put(cipherSmall.charAt(i), beginSmallLetter++);
-      cipherMap.put(cipherCapital.charAt(i), beginCapitalLetter++);
+    /**
+     * TODO remove main and make JUnit Testing
+     */
+    public static void main(String[] args) {
+        String a = encode("defend the east wall of the castle", "phqgiumeaylnofdxjkrcvstzwb");
+        String b = decode(a, "phqgiumeaylnofdxjkrcvstzwb");
+        System.out.println(b);
     }
-
-    for (int i = 0; i < encryptedMessage.length(); i++) {
-      if (Character.isAlphabetic(encryptedMessage.charAt(i)))
-        decoded.append(cipherMap.get(encryptedMessage.charAt(i)));
-      else decoded.append(encryptedMessage.charAt(i));
-    }
-
-    return decoded.toString();
-  }
-
-  /** TODO remove main and make JUnit Testing */
-  public static void main(String[] args) {
-    String a = encode("defend the east wall of the castle", "phqgiumeaylnofdxjkrcvstzwb");
-    String b = decode(a, "phqgiumeaylnofdxjkrcvstzwb");
-    System.out.println(b);
-  }
 }

Ciphers/Vigenere.java

@@ -8,55 +8,55 @@ package Ciphers;
  */
 public class Vigenere {
 
-  public static String encrypt(final String message, final String key) {
+    public static String encrypt(final String message, final String key) {
 
-    StringBuilder result = new StringBuilder();
+        StringBuilder result = new StringBuilder();
 
-    for (int i = 0, j = 0; i < message.length(); i++) {
-      char c = message.charAt(i);
-      if (Character.isLetter(c)) {
-        if (Character.isUpperCase(c)) {
-          result.append((char) ((c + key.toUpperCase().charAt(j) - 2 * 'A') % 26 + 'A'));
+        for (int i = 0, j = 0; i < message.length(); i++) {
+            char c = message.charAt(i);
+            if (Character.isLetter(c)) {
+                if (Character.isUpperCase(c)) {
+                    result.append((char) ((c + key.toUpperCase().charAt(j) - 2 * 'A') % 26 + 'A'));
 
-        } else {
-          result.append((char) ((c + key.toLowerCase().charAt(j) - 2 * 'a') % 26 + 'a'));
+                } else {
+                    result.append((char) ((c + key.toLowerCase().charAt(j) - 2 * 'a') % 26 + 'a'));
+                }
+            } else {
+                result.append(c);
+            }
+            j = ++j % key.length();
         }
-      } else {
-        result.append(c);
-      }
-      j = ++j % key.length();
+        return result.toString();
     }
-    return result.toString();
-  }
 
-  public static String decrypt(final String message, final String key) {
-    StringBuilder result = new StringBuilder();
+    public static String decrypt(final String message, final String key) {
+        StringBuilder result = new StringBuilder();
 
-    for (int i = 0, j = 0; i < message.length(); i++) {
+        for (int i = 0, j = 0; i < message.length(); i++) {
 
-      char c = message.charAt(i);
-      if (Character.isLetter(c)) {
-        if (Character.isUpperCase(c)) {
-          result.append((char) ('Z' - (25 - (c - key.toUpperCase().charAt(j))) % 26));
+            char c = message.charAt(i);
+            if (Character.isLetter(c)) {
+                if (Character.isUpperCase(c)) {
+                    result.append((char) ('Z' - (25 - (c - key.toUpperCase().charAt(j))) % 26));
 
-        } else {
-          result.append((char) ('z' - (25 - (c - key.toLowerCase().charAt(j))) % 26));
+                } else {
+                    result.append((char) ('z' - (25 - (c - key.toLowerCase().charAt(j))) % 26));
+                }
+            } else {
+                result.append(c);
+            }
+
+            j = ++j % key.length();
         }
-      } else {
-        result.append(c);
-      }
-
-      j = ++j % key.length();
+        return result.toString();
     }
-    return result.toString();
-  }
 
-  public static void main(String[] args) {
-    String text = "Hello World!";
-    String key = "itsakey";
-    System.out.println(text);
-    String ciphertext = encrypt(text, key);
-    System.out.println(ciphertext);
-    System.out.println(decrypt(ciphertext, key));
-  }
+    public static void main(String[] args) {
+        String text = "Hello World!";
+        String key = "itsakey";
+        System.out.println(text);
+        String ciphertext = encrypt(text, key);
+        System.out.println(ciphertext);
+        System.out.println(decrypt(ciphertext, key));
+    }
 }

Ciphers/affineCipher.java

@@ -1,83 +0,0 @@
-package Ciphers;
-class affineCipher
-{
- 
-    // Key values of a and b
-    static int a = 17;
-    static int b = 20;
- 
-    static String encryptMessage(char[] msg)
-    {
-        /// Cipher Text initially empty
-        String cipher = "";
-        for (int i = 0; i < msg.length; i++)
-        {
-            // Avoid space to be encrypted
-            /* applying encryption formula ( a x + b ) mod m
-            {here x is msg[i] and m is 26} and added 'A' to
-            bring it in range of ascii alphabet[ 65-90 | A-Z ] */
-            if (msg[i] != ' ')
-            {
-                cipher = cipher
-                        + (char) ((((a * (msg[i] - 'A')) + b) % 26) + 'A');
-            } else // else simply append space character
-            {
-                cipher += msg[i];
-            }
-        }
-        return cipher;
-    }
- 
-    static String decryptCipher(String cipher)
-    {
-        String msg = "";
-        int a_inv = 0;
-        int flag = 0;
- 
-        //Find a^-1 (the multiplicative inverse of a
-        //in the group of integers modulo m.)
-        for (int i = 0; i < 26; i++)
-        {
-            flag = (a * i) % 26;
- 
-            // Check if (a*i)%26 == 1,
-            // then i will be the multiplicative inverse of a
-            if (flag == 1)
-            {
-                a_inv = i;
-            }
-        }
-        for (int i = 0; i < cipher.length(); i++)
-        {
-            /*Applying decryption formula a^-1 ( x - b ) mod m
-            {here x is cipher[i] and m is 26} and added 'A'
-            to bring it in range of ASCII alphabet[ 65-90 | A-Z ] */
-            if (cipher.charAt(i) != ' ')
-            {
-                msg = msg + (char) (((a_inv *
-                        ((cipher.charAt(i) + 'A' - b)) % 26)) + 'A');
-            }
-            else //else simply append space character
-            {
-                msg += cipher.charAt(i);
-            }
-        }
- 
-        return msg;
-    }
- 
-    // Driver code
-    public static void main(String[] args)
-    {
-        String msg = "AFFINE CIPHER";
- 
-        // Calling encryption function
-        String cipherText = encryptMessage(msg.toCharArray());
-        System.out.println("Encrypted Message is : " + cipherText);
- 
-        // Calling Decryption function
-        System.out.println("Decrypted Message is: " + decryptCipher(cipherText));
- 
-    }
-}
-