Encrypt using RSA in Java

package com.emjay.util.encryption;

import java.io.IOException;

import java.security.KeyPair;

import java.security.KeyPairGenerator;

import java.security.NoSuchAlgorithmException;

import java.security.PrivateKey;

import java.security.Provider;

import java.security.PublicKey;

import java.security.Security;

import javax.crypto.Cipher;

public class EncryptionUtil {

protected static final String ALGORITHM = "RSA";

public static void main(String[] args) throws Exception {

Provider[] providerArray = Security.getProviders();

// Iterate through the default providers and print the name

for(int i=0; i

System.out.println("Built in Providers: (" + i + ")" + providerArray[i]);

}

// Generate the public and private key

KeyPair keyPair = EncryptionUtil.generateKey();

PublicKey publicKey = keyPair.getPublic();

PrivateKey privateKey = keyPair.getPrivate();

// Encrypt the String

byte[] encryptedBytes = encrypt(decodeBASE64("ABCDEFGH"), publicKey);

String encryptedString = encodeBASE64(encryptedBytes);

System.out.println("Encrypted String is: " + encryptedString);

// Decrypt the String

System.out.println("Decrypted String is: " + encodeBASE64(decrypt(encryptedBytes, privateKey)));

}

private static KeyPair generateKey() throws NoSuchAlgorithmException {

KeyPairGenerator keyGen = KeyPairGenerator.getInstance(ALGORITHM);

keyGen.initialize(1024);

KeyPair key = keyGen.generateKeyPair();

return key;

}

public static byte[] encrypt(byte[] text, PublicKey key) throws Exception {

byte[] cipherText = null;

Cipher cipher = Cipher.getInstance("RSA/ECB/PKCS1Padding");

//System.out.println("Provider is: " + cipher.getProvider().getInfo());

cipher.init(Cipher.ENCRYPT_MODE, key);

cipherText = cipher.doFinal(text);

return cipherText;

}

private static byte[] decrypt(byte[] text, PrivateKey key) throws Exception {

byte[] dectyptedText = null;

Cipher cipher = Cipher.getInstance("RSA/ECB/PKCS1Padding");

cipher.init(Cipher.DECRYPT_MODE, key);

dectyptedText = cipher.doFinal(text);

return dectyptedText;

}

private static String encodeBASE64(byte[] bytes) {

// Implement this method to convert byte array to String back

}

private static byte[] decodeBASE64(String text) throws IOException {

// Implement this method to convert String to byte array

}

}

* Please see Base64Coder from http://www.source-code.biz/base64coder/java/