Encryption and Decryption in .net

Encryption:
using System.Security.Cryptography;//add reference

private string EncryptString(string strText, string strEncrKey) 
{ 
    byte[] byKey = { }; 
    byte[] IV = { 0x12, 0x34, 0x56, 0x78, 0x90, 0xab, 0xcd, 0xef }; 
    try 
    { 
        byKey = System.Text.Encoding.UTF8.GetBytes(strEncrKey.Substring(0, 8)); 
        DESCryptoServiceProvider Des = new DESCryptoServiceProvider(); 
        byte[] inputByteArray = Encoding.UTF8.GetBytes(strText); 
        MemoryStream Ms = new MemoryStream(); 
        CryptoStream Cs = new CryptoStream(Ms, Des.CreateEncryptor(byKey, IV), CryptoStreamMode.Write); 
        Cs.Write(inputByteArray, 0, inputByteArray.Length); 
        Cs.FlushFinalBlock(); 
        return Convert.ToBase64String(Ms.ToArray()); 
     } 
     catch (Exception ex) 
     { 
          return "Error Occured while Encrypting the '" + strText + "'"; 
     } 
}

private string EncryptText(string EncText)
{
    return EncryptString(EncText, "&%#@?,:*");
}

protected void Button1_Click(object sender, EventArgs e)
{
     try
     { 
         TextBox2.Text = EncryptText(TextBox1.Text);
     }
     catch (Exception)
     { }
}


Decryption:

private string DecryptString(string strText, string sDecrKey)
{
      byte[] byKey = { };
      byte[] IV = { 0x12, 0x34, 0x56, 0x78, 0x90, 0xab, 0xcd, 0xef };
      byte[] inputByteArray = new byte[strText.Length + 1];
      try
      {
          byKey = System.Text.Encoding.UTF8.GetBytes(sDecrKey.Substring(0, 8));
          DESCryptoServiceProvider Des = new DESCryptoServiceProvider();
          inputByteArray = Convert.FromBase64String(strText);
          MemoryStream Ms = new MemoryStream();
          CryptoStream Cs = new CryptoStream(Ms, Des.CreateDecryptor(byKey, IV), CryptoStreamMode.Write);
          Cs.Write(inputByteArray, 0, inputByteArray.Length);
          Cs.FlushFinalBlock();
          System.Text.Encoding encoding = System.Text.Encoding.UTF8;
          return encoding.GetString(Ms.ToArray());
      }
     catch (Exception ex)
     {
          return "Error Occured while Decrypting the '" + strText + "'";
     }
}

public string DecryptText(string DecText)
{
     return DecryptString(DecText, "&%#@?,:*");
}

protected void Button2_Click(object sender, EventArgs e)
{
    try
    {
         TextBox3.Text = DecryptText(TextBox2.Text);
    }
    catch (Exception)
    { }
}