Add Encriptin Decription Program

lcmProgram/EncriptionAndDecription/CipherMenu.java

@@ -0,0 +1,104 @@
+
+package EncriptionAndDecription;
+import java.util.Scanner;
+
+public class CipherMenu {
+    public static void main(String[] args) {
+        Scanner sc = new Scanner(System.in);
+
+        System.out.println("Encryption Techniques Menu");
+        System.out.println("1. Additive Cipher");
+        System.out.println("2. Multiplicative Cipher");
+        System.out.println("3. Affine Cipher");
+        System.out.println("4. Exit");
+        System.out.print("Enter your choice: ");
+        int choice = sc.nextInt();
+        sc.nextLine(); // Consume the newline character
+
+        switch (choice) {
+            case 1:
+                System.out.print("Enter the text: ");
+                String additiveText = sc.nextLine();
+                System.out.print("Enter the shift value: ");
+                int shiftValue = sc.nextInt();
+                sc.nextLine(); // Consume the newline character
+                String additiveCipher = additiveCipher(additiveText, shiftValue);
+                System.out.println("Additive Cipher: " + additiveCipher);
+                break;
+
+            case 2:
+                System.out.println("Multiplicative Cipher");
+                System.out.print("Enter the plaintext: ");
+                String multiplicativeText = sc.nextLine();
+                System.out.print("Enter the shift value: ");
+                int multiplicativeShift = sc.nextInt();
+                sc.nextLine(); // Consume the newline character
+                String multiplicativeCipher = multiplicativeCipher(multiplicativeText, multiplicativeShift);
+                System.out.println("Multiplicative Cipher: " + multiplicativeCipher);
+                break;
+
+            case 3:
+                System.out.println("Affine Cipher");
+                System.out.print("Enter the text: ");
+                String affineText = sc.nextLine();
+                String affineCipher = affineCipher(affineText);
+                System.out.println("Affine Cipher: " + affineCipher);
+                break;
+
+            case 4:
+                System.out.println("Exiting the program.");
+                break;
+
+            default:
+                System.out.println("Invalid choice. Please select a valid option.");
+        }
+
+        sc.close();
+    }
+
+    // Additive Cipher, Multiplicative Cipher, and Affine Cipher methods here...
+
+    public static String additiveCipher(String text, int s) {
+        StringBuilder result = new StringBuilder();
+
+        for (int i = 0; i < text.length(); i++) {
+            char ch = text.charAt(i);
+            if (Character.isUpperCase(ch)) {
+                ch = (char) (((ch - 'A' + s) % 26) + 'A');
+            } else if (Character.isLowerCase(ch)) {
+                ch = (char) (((ch - 'a' + s) % 26) + 'a');
+            }
+            result.append(ch);
+        }
+        return result.toString();
+    }
+
+    public static String multiplicativeCipher(String text, int shift) {
+        StringBuilder result = new StringBuilder();
+
+        for (int i = 0; i < text.length(); i++) {
+            char ch = text.charAt(i);
+            if (Character.isLetter(ch)) {
+                ch = (char) (((ch - 'a') * shift % 26) + 'a');
+            }
+            result.append(ch);
+        }
+        return result.toString();
+    }
+
+    public static String affineCipher(String text) {
+        int a = 17;
+        int b = 20;
+        StringBuilder result = new StringBuilder();
+
+        for (char ch : text.toCharArray()) {
+            if (Character.isLetter(ch)) {
+                char encryptedChar = (char) (((a * (ch - 'A') + b) % 26) + 'A');
+                result.append(encryptedChar);
+            } else {
+                result.append(ch);
+            }
+        }
+        return result.toString();
+    }
+}