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2020-10-24 10:23:28 +00:00
parent a23bac99e8
commit 5d59a2e828
219 changed files with 13758 additions and 14582 deletions
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90
ciphers/Vigenere.java
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@@ -2,66 +2,60 @@ package ciphers;
/**
* A Java implementation of Vigenere Cipher.
* @author straiffix
*
* @author straiffix
*/
public class Vigenere {
public static String encrypt(final String message, final String key) {
public class Vigenere {
String result = "";
public static String encrypt(final String message, final String key)
{
for (int i = 0, j = 0; i < message.length(); i++) {
char c = message.charAt(i);
if (Character.isLetter(c)) {
if (Character.isUpperCase(c)) {
result += (char) ((c + key.toUpperCase().charAt(j) - 2 * 'A') % 26 + 'A');
String result = "";
for (int i = 0, j = 0; i < message.length(); i++) {
char c = message.charAt(i);
if (Character.isLetter(c)){
if(Character.isUpperCase(c)) {
result += (char) ((c + key.toUpperCase().charAt(j) - 2 * 'A') % 26 + 'A');
} else {
result += (char) ((c + key.toLowerCase().charAt(j) - 2 * 'a') % 26 + 'a');
}
} else {
result+=c;
}
j = ++j % key.length();
} else {
result += (char) ((c + key.toLowerCase().charAt(j) - 2 * 'a') % 26 + 'a');
}
return result;
} else {
result += c;
}
j = ++j % key.length();
}
return result;
}
public static String decrypt( final String message, final String key)
{
String result ="";
public static String decrypt(final String message, final String key) {
String result = "";
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 += ((char)('Z'-(25-(c-key.toUpperCase().charAt(j)))%26));
} else {
result += ((char)('z'-(25-(c-key.toLowerCase().charAt(j)))%26));
}
} else {
result+=c;
}
j = ++j % key.length();
char c = message.charAt(i);
if (Character.isLetter(c)) {
if (Character.isUpperCase(c)) {
result += ((char) ('Z' - (25 - (c - key.toUpperCase().charAt(j))) % 26));
} else {
result += ((char) ('z' - (25 - (c - key.toLowerCase().charAt(j))) % 26));
}
return result;
}
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));
} else {
result += c;
}
j = ++j % key.length();
}
return result;
}
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));
}
}