Function DeCrypt(ByVal data As String, ByVal key As String) As String
        Dim Mymemorystream As MemoryStream = New MemoryStream
 
        Dim DES As DESCryptoServiceProvider = New DESCryptoServiceProvider
        DES.Key = GetBytesFromString(key)
        DES.IV = DES.Key
 
        Dim MyCryptostream As CryptoStream = New CryptoStream(Mymemorystream, _
          DES.CreateDecryptor(), CryptoStreamMode.Write)
        Dim writer As StreamWriter = New StreamWriter(MyCryptostream)
        writer.Write(data)
 
        MyCryptostream.FlushFinalBlock()           
        Mymemorystream.Seek(0, SeekOrigin.Begin)    
 
        Dim reader As StreamReader = New StreamReader(Mymemorystream)
        Dim CryptData As String = reader.ReadToEnd  'auslesen des 
        ' Verschlüsselten Wertes aus Speicher
 
        MyCryptostream.Close()
        Mymemorystream.Close()
 
        Return CryptData
 
    End Function