Hi Friend,

Try the following code:

import java.io.*;
import java.security.*;
import javax.crypto.*;

class EncryptAndDecrypt {

public static void main (String[] args) throws Exception{
KeyPairGenerator keygenerator = KeyPairGenerator.getInstance("RSA");
SecureRandom random = SecureRandom.getInstance("SHA1PRNG", "SUN");
keygenerator.initialize(1024, random);

KeyPair keypair = keygenerator.generateKeyPair();
PrivateKey privateKey = keypair.getPrivate();
PublicKey publicKey = keypair.getPublic();
Cipher cipher = Cipher.getInstance("RSA");

cipher.init(Cipher.ENCRYPT_MODE, publicKey);
String st= "roseindia";
byte[] cleartext = null;
cleartext = st.getBytes();
byte[] ciphertext = null;
ciphertext = cipher.doFinal(cleartext);
System.out.println("the encrypted text is: " + ciphertext.toString());

cipher.init(Cipher.DECRYPT_MODE, privateKey);
byte[] cleartext1 = cipher.doFinal(ciphertext);
System.out.println("the decrypted cleartext is: " + new String(cleartext1));
}
}

Thanks

import java.security.*; import javax.crypto.*; import javax.crypto.spec.DESKeySpec;

class EncryptAndDecrypt {

public static void main (String[] args) throws Exception{ //KeyPairGenerator keygenerator = KeyPairGenerator.getInstance("RC4"); SecretKeyFactory key = SecretKeyFactory.getInstance("DES"); SecureRandom random = SecureRandom.getInstance("SHA1PRNG", "SUN"); //keygenerator.initialize(1024, random); byte[] desKeyData = { (byte)0x01, (byte)0x02, (byte)0x03, (byte)0x04, (byte)0x05, (byte)0x06, (byte)0x07, (byte)0x08 }; DESKeySpec desKeySpec = new DESKeySpec(desKeyData);

//KeyPair keypair = keygenerator.generateKeyPair(); Key keys = key.generateSecret(desKeySpec); //PrivateKey privateKey = keypair.getPrivate(); //PublicKey publicKey = keypair.getPublic();

Cipher cipher = Cipher.getInstance("DES");

System.out.println("publicKey="+keys.toString()); //System.out.println("privateKey="+privateKey.toString());

cipher.init(Cipher.ENCRYPT_MODE, keys); String st= "Welcome"; byte[] cleartext = null; cleartext = st.getBytes(); byte[] ciphertext = null; ciphertext = cipher.doFinal(cleartext); System.out.println("the encrypted text is: " + ciphertext.toString());

cipher.init(Cipher.DECRYPT_MODE, keys); byte[] cleartext1 = cipher.doFinal(ciphertext); System.out.println("the decrypted cleartext is: " + new String(cleartext1)); } }

http://www.roseindia.net/answers/viewqa/Java-Beginners/26017-Java-Encryption-using-AES-with-key-password-.html

http://www.roseindia.net/answers/viewqa/Java-Beginners/26020-AES-Decryption-using-key-password-.html