Not able to load decrypted asset bundle

Hi there!!!
I had been trying to encrypt/decrypt an asset bundle and did that successfully.
Here is my Cryptor class that handles all cryption business >>



using UnityEngine;
using System.Collections;
using System.Security.Cryptography;
using System.IO;
using System.Text;

public class TripleDESCryption : MonoBehaviour {
	
	[SerializeField] string Key;
	
	
	string EncrypInputPath , EncrypOutputPath, DecrypOutputPath, AssetBundlePath;



	void Awake(){
		Key = GenerateKey();
		
		EncrypInputPath = System.IO.Path.Combine(Application.streamingAssetsPath , "cube.unity3d");;
		EncrypOutputPath = System.IO.Path.Combine(Application.streamingAssetsPath , "Encryptedcube.unity3d");
		
		DecrypOutputPath = System.IO.Path.Combine(Application.streamingAssetsPath , "Decryptedcube.unity3d");
		
		AssetBundlePath = System.IO.Path.Combine("file:///" + Application.streamingAssetsPath , "Decryptedcube.unity3d");
	}


	void Start(){
		Encrypt(EncrypInputPath , EncrypOutputPath , Key);
		Decrypt(EncrypOutputPath , DecrypOutputPath , Key);
		StartCoroutine(LoadAssetBundleScene());
	}

	


	IEnumerator LoadAssetBundleScene(){
		WWW ABwww = new WWW(AssetBundlePath);

		yield return ABwww;


		if(ABwww.error != null)
			Debug.LogError(ABwww.error);
		

		
		AssetBundle SceneAB = ABwww.assetBundle;
		
		SceneAB.LoadAll();
		
		Application.LoadLevel("cube");
	}
	
	
	
	
	
	

	string GenerateKey(){
		DESCryptoServiceProvider desCrypto = (DESCryptoServiceProvider)DESCryptoServiceProvider.Create();
		return ASCIIEncoding.ASCII.GetString(desCrypto.Key);
	}
	



	void Encrypt(string input , string output , string strHash){
		FileStream inStream , outStream;
		CryptoStream CryStream;
		
		TripleDESCryptoServiceProvider TDC = new TripleDESCryptoServiceProvider();
		MD5CryptoServiceProvider md5 = new MD5CryptoServiceProvider();
		
		byte[] byteHash , byteTexto;
		
		inStream = new FileStream(input , FileMode.Open , FileAccess.Read);
		outStream = new FileStream(output , FileMode.OpenOrCreate , FileAccess.Write);
		
		byteHash = md5.ComputeHash(ASCIIEncoding.ASCII.GetBytes(strHash));
		
		byteTexto = File.ReadAllBytes(input);
		
		md5.Clear();
		
		TDC.Key = byteHash;
		TDC.Mode = CipherMode.ECB;
		
		CryStream = new CryptoStream(outStream , TDC.CreateEncryptor() , CryptoStreamMode.Write);
		
		int bytesRead;
		long length , position = 0;
		length = inStream.Length;
		
		
		while(position < length){
			bytesRead = inStream.Read(byteTexto , 0 , byteTexto.Length);
			position += bytesRead;
			
			CryStream.Write(byteTexto , 0 , bytesRead);
		}
		
		inStream.Close();
		outStream.Close();
		
	}
	
	
	

	void Decrypt(string input , string output , string strHash){
		FileStream inStream , outStream;
		CryptoStream CryStream;
		
		TripleDESCryptoServiceProvider TDC = new TripleDESCryptoServiceProvider();
		MD5CryptoServiceProvider md5 = new MD5CryptoServiceProvider();
		
		byte[] byteHash , byteTexto;
		
		inStream = new FileStream(input , FileMode.Open , FileAccess.Read);
		outStream = new FileStream(output , FileMode.OpenOrCreate , FileAccess.Write);
		
		byteHash = md5.ComputeHash(ASCIIEncoding.ASCII.GetBytes(strHash)); 
		
		byteTexto = File.ReadAllBytes(input);
		
		md5.Clear();
		
		TDC.Key = byteHash;
		TDC.Mode = CipherMode.ECB;
		
		CryStream = new CryptoStream(outStream , TDC.CreateDecryptor() , CryptoStreamMode.Write);
		
		int bytesRead;
		long length , position = 0;
		length = inStream.Length;
		
		while(position < length){
			bytesRead = inStream.Read(byteTexto , 0 , byteTexto.Length);
			position += bytesRead;
			
			CryStream.Write(byteTexto , 0 , bytesRead);
		}
		
		inStream.Close();
		outStream.Close();
	}
}

I tried encryption/Decryption with other files such as music,video,txt,etc…In that case
the Decrypted file was as good as the Orignal file and was good to go.
But in case of asset bundle the decrypted asset bundle wont load at all and come up with the specified error
Does anyone know, where the problem is???

When I try to load the decrypted asset bundle with WWW , the asset bundle does not loads and Unity shows the following error >>>

do not encrypt the origin assetbundle, try to encrypt first and make assetbundle after that ,assetbundle means just pack the file ,before that you almost can do anything