Monday, August 13, 2012

Triple DES Encryption implementation compatible between Java and .NET

 Encryption of sensitive data is very important in most of the software applications today. In this feed I’ll show you how to encrypt and decrypt a string data using the encryption classes. The algorithm using one key to encrypt and the same key to decrypt the data. I’ll be using the TripleDES encryption algorithm which is considered to be very secure. It performs three times as much encryption as the standard DES.

.NET (C#) Implementation

using System;
using System.Diagnostics;
using System.Security.Cryptography;
using System.Text;
public class TripleDESImplementation
    //Encryption Key
    private byte[] EncryptionKey { get; set; }
    // The Initialization Vector for the DES encryption routine
    private byte[] IV { get; set; }

    /// <summary>
    /// Constructor for TripleDESImplementation class
    /// </summary>
    /// <param name="encryptionKey">The 24-byte encryption key (24 character ASCII)</param>
    /// <param name="IV">The 8-byte DES encryption initialization vector (8 characters ASCII)</param>
    public TripleDESImplementation(string encryptionKey, string IV)

        if (string.IsNullOrEmpty(encryptionKey))
            throw new ArgumentNullException("'encryptionKey' parameter cannot be null.", "encryptionKey");
        if (string.IsNullOrEmpty(IV))
            throw new ArgumentException("'IV' parameter cannot be null or empty.", "IV");

        EncryptionKey = Encoding.ASCII.GetBytes(encryptionKey);
        // Ensures length of 24 for encryption key
        Trace.Assert(EncryptionKey.Length == 24, "Encryption key must be exactly 24 characters of ASCII text (24 bytes)");

        this.IV = Encoding.ASCII.GetBytes(IV);
        // Ensures length of 8 for init. vector
        Trace.Assert(IV.Length == 8, "Init. vector must be exactly 8 characters of ASCII text (8 bytes)");

    /// <summary>
    /// Encrypts a text block
    /// </summary>
    public string Encrypt(string textToEncrypt)
        TripleDESCryptoServiceProvider tdes = new TripleDESCryptoServiceProvider();
        tdes.Key = EncryptionKey;
        tdes.IV = IV;

        byte[] buffer = Encoding.ASCII.GetBytes(textToEncrypt);
        return Convert.ToBase64String(tdes.CreateEncryptor().TransformFinalBlock(buffer, 0, buffer.Length));

    /// <summary>
    /// Decrypts an encrypted text block
    /// </summary>
    public string Decrypt(string textToDecrypt)
        byte[] buffer = Convert.FromBase64String(textToDecrypt);

        TripleDESCryptoServiceProvider des = new TripleDESCryptoServiceProvider();
        des.Key = EncryptionKey;
        des.IV = IV;

        return Encoding.ASCII.GetString(des.CreateDecryptor().TransformFinalBlock(buffer, 0, buffer.Length));

Java Implementation


import javax.crypto.Cipher;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;

public class TripleDesImplementation {
    private String key;
    private String initializationVector;
    public TripleDesImplementation(String key, String initializationVector)
        this.key = key;
        this.initializationVector = initializationVector;

    public String encryptText(String plainText) throws Exception{
    //----  Use the same 3DES key and IV-------------------------
      byte[] plaintext = plainText.getBytes();
      byte[] tdesKeyData = key.getBytes();

      byte[] myIV = initializationVector.getBytes();

      Cipher c3des = Cipher.getInstance("DESede/CBC/PKCS5Padding");
      SecretKeySpec    myKey = new SecretKeySpec(tdesKeyData, "DESede");
      IvParameterSpec ivspec = new IvParameterSpec(myIV);

      c3des.init(Cipher.ENCRYPT_MODE, myKey, ivspec);
      byte[] cipherText = c3des.doFinal(plaintext);

      return Base64Coder.encodeString(new String(cipherText));