String encryption and decryption

cs_encryption

/******************************************************************************************************
FOR ENCRYPT AND DECRYPT METHODS TO WORK, THE KEY, INITIALIZATION
VECTOR (IV), AND BYTE ARRAY HAS TO BE IDENTICAL.  OTHERWISE THE
PADDING ERROR WILL BE ENCOUNTERED.
*******************************************************************************************************/

public static string EncryptURLParam(string authKey, string textToEncrypt)
{
  string strEncrypt = string.Empty;

	try
	{
		using (Rijndael rDel = Rijndael.Create())
		{
			rDel.Key = Encoding.ASCII.GetBytes(authKey); //32bytes
			rDel.IV = Encoding.ASCII.GetBytes(authKey.Substring(0,16)); //16bytes
			ICryptoTransform encryptor = rDel.CreateEncryptor(rDel.Key, rDel.IV);
			using (MemoryStream msEncrypt = new MemoryStream())
			{
				using (CryptoStream csEncrypt = new CryptoStream(msEncrypt, encryptor, CryptoStreamMode.Write))
				{
					using (StreamWriter swEncrypt = new StreamWriter(csEncrypt))
					{
						swEncrypt.Write(textToEncrypt);
					}
				}

				byte[] bt = msEncrypt.ToArray();                        
				strEncrypt = HttpContext.Current.Server.UrlEncode(Convert.ToBase64String(bt));
			}
		}
	}
	catch
	{
		//do nothing
	}

	return strEncrypt;
}

public static string DecryptURLParam(string authKey, string textToDecrypt)
{
	string decryptedId = string.Empty;

	try
	{
		//when urldecode is called, '+' characters are converted to a space
		//thus the need to replace those empty spaces to '+' again
		byte[] bt = Convert.FromBase64String(HttpContext.Current.Server.UrlDecode(textToDecrypt).Replace(' ', '+'));

		using (Rijndael rDel = Rijndael.Create())
		{
			rDel.Key = Encoding.ASCII.GetBytes(authKey);  //32bytes
			rDel.IV = Encoding.ASCII.GetBytes(authKey.Substring(0, 16)); //16bytes
			ICryptoTransform decryptor = rDel.CreateDecryptor(rDel.Key, rDel.IV);
			using (MemoryStream msDecrypt = new MemoryStream(bt))
			{
				using (CryptoStream csDecrypt = new CryptoStream(msDecrypt, decryptor, CryptoStreamMode.Read))
				{
					using (StreamReader srDecrypt = new StreamReader(csDecrypt))
					{
						decryptedId = srDecrypt.ReadToEnd();
					}
				}
			}
		}
	}
	catch
	{
		//do nothing
	}

	return decryptedId;
}