Unterschiede

Hier werden die Unterschiede zwischen zwei Versionen angezeigt.

--- j11:verschluesselung:start [2023/06/13 15:01] – Martin Pabst
+++ j11:verschluesselung:start [2023/06/13 15:08] (aktuell) – [Cäsar-Verschlüsselung] Martin Pabst
@@ Zeile 1: / Zeile 1: @@
 ====== Verschlüsselung ======
+===== Cäsar-Verschlüsselung =====
 <HTML>
@@ Zeile 21: / Zeile 22: @@
 class Cäsar {
-   int keyIndex;
+   int keyOffset;
    String alphabet = "abcdefghijklmnopqrstuvwxyzäöüßABCDEFGHIJKLMNOPQRSTUVWXYZÄÖÜ ";
    public Cäsar(char key) {
-      this.keyIndex = alphabet.indexOf(key);
+      this.keyOffset = alphabet.indexOf(key);
    }
@@ Zeile 34: / Zeile 35: @@
          char plainCharacter = plaintext.charAt(index);
          int charIndex = alphabet.indexOf(plainCharacter);
-         charIndex = (charIndex + keyIndex) % alphabet.length();
+         charIndex = (charIndex + keyOffset) % alphabet.length();
          ciphertext += alphabet.charAt(charIndex);
@@ Zeile 50: / Zeile 51: @@
          char plainCharacter = ciphertext.charAt(index);
          int charIndex = alphabet.indexOf(plainCharacter);
-         charIndex = (charIndex - keyIndex + alphabet.length()) % alphabet.length();
+         charIndex = (charIndex - keyOffset + alphabet.length()) % alphabet.length();
          plaintext += alphabet.charAt(charIndex);
+      }
+      return plaintext;
+   }
+}</script>
+</div>
+</HTML>
+===== Vigenère-Verschlüsselung =====
+<HTML>
+<div class="java-online" style="height: 70vh; width: 100%" data-java-online="{'withBottomPanel': false, 'id': 'Vigenere'}">
+<script type="text/plain" title="Main.java">
+String schlüssel = Input.readString("Bitte geben Sie den Schlüssel ein:");
+Vigenere vigenere = new Vigenere(schlüssel);
+String plaintext = Input.readString("Welcher Text soll verschlüsselt werden?");
+vigenere.encrypt(plaintext);
+String ciphertext = vigenere.encrypt(plaintext);
+println("\nVerschlüsselter Text:", Color.chocolate);
+println(ciphertext);
+println("\nZur Sicherheit nochmals entschlüsselt:", Color.chocolate);
+println(vigenere.decrypt(ciphertext));
+class Vigenere {
+   String key;
+   String alphabet = "abcdefghijklmnopqrstuvwxyzäöüßABCDEFGHIJKLMNOPQRSTUVWXYZÄÖÜ ";
+   public Vigenere(String key) {
+      this.key = key;
+   }
+   public String encrypt(String plaintext) {
+      String ciphertext = "";
+      int keyIndex = 0;
+      for (int index = 0; index < plaintext.length(); index++) {
+         char plainCharacter = plaintext.charAt(index);
+         int charIndex = alphabet.indexOf(plainCharacter);
+         int keyOffset = alphabet.indexOf(key.charAt(keyIndex));
+         charIndex = (charIndex + keyOffset) % alphabet.length();
+         ciphertext += alphabet.charAt(charIndex);
+         keyIndex = (keyIndex + 1) % key.length();
+      }
+      return ciphertext;
+   }
+   public String decrypt(String ciphertext) {
+      String plaintext = "";
+      int keyIndex = 0;
+      for (int index = 0; index < ciphertext.length(); index++) {
+         char plainCharacter = ciphertext.charAt(index);
+         int charIndex = alphabet.indexOf(plainCharacter);
+         int keyOffset = alphabet.indexOf(key.charAt(keyIndex));
+         charIndex = (charIndex - keyOffset + alphabet.length()) % alphabet.length();
+         plaintext += alphabet.charAt(charIndex);
+         keyIndex = (keyIndex + 1) % key.length();
       }