Untitled Note
By: Anonymous10/17/20223 views Public Note
package aes;
import java.security.SecureRandom;
import java.util.Random;
import javax.crypto.Cipher;
import javax.crypto.KeyGenerator;
import javax.crypto.SecretKey;
import javax.crypto.spec.SecretKeySpec;
import javax.swing.JOptionPane;
public class Main {
byte[] skey = new byte[1000];
String skeyString;
static byte[] raw;
String inputMessage, encryptedData, decryptedMessage;
public Main() {
try {
generateSymmetricKey();
inputMessage = JOptionPane.showInputDialog(null, "Enter message to encrypt");
byte[] ibyte = inputMessage.getBytes();
byte[] ebyte = encrypt(raw, ibyte);
String encryptedData = new String(ebyte);
System.out.println("Encrypted message:" encryptedData);
JOptionPane.showMessageDialog(null, "Encrypted Data" "\n" encryptedData);
byte[] dbyte = decrypt(raw, ebyte);
String decryptedMessage = new String(dbyte);
System.out.println("Decrypted message:" decryptedMessage);
JOptionPane.showMessageDialog(null, "Decrypted Data" "\n" decryptedMessage);
} catch (Exception e) {
System.out.println(e);
}
}
void generateSymmetricKey() {
try {
Random r = new Random();
int num = r.nextInt(10000);
String knum = String.valueOf(num);
byte[] knumb = knum.getBytes();
skey = getRawKey(knumb);
skeyString = new String(skey);
System.out.println("DES Symmetric key = " skeyString);
} catch (Exception e) {
System.out.println(e);
}
}
private static byte[] getRawKey(byte[] seed) throws Exception {
KeyGenerator kgen = KeyGenerator.getInstance("DES");
SecureRandom sr = SecureRandom.getInstance("SHA1PRNG");
sr.setSeed(seed);
kgen.init(56, sr);
SecretKey skey = kgen.generateKey();
raw = skey.getEncoded();
return raw;
}
private static byte[] encrypt(byte[] raw, byte[] clear) throws Exception {
SecretKeySpec skeySpec = new SecretKeySpec(raw, "DES");
Cipher cipher = Cipher.getInstance("DES");
cipher.init(Cipher.ENCRYPT_MODE, skeySpec);
byte[] encrypted = cipher.doFinal(clear);
return encrypted;
}
private static byte[] decrypt(byte[] raw, byte[] encrypted) throws Exception {
SecretKeySpec skeySpec = new SecretKeySpec(raw, "DES");
Cipher cipher = Cipher.getInstance("DES");
cipher.init(Cipher.DECRYPT_MODE, skeySpec);
byte[] decrypted = cipher.doFinal(encrypted);
return decrypted;
}
public static void main(String[] args) {
Main des;
des = new Main();
}
}
package caesar.cipher;
public class CaesarCipher {
public static StringBuffer encrypt(String text,int s)
{
StringBuffer result = new StringBuffer();
for(int i=0;ipermutation = new ArrayList<>();
for(int i = 0; i 0