private async void Start()
        {
            StatusString = "Generating key file...";
            try
            {
                long bytesCount = new FileInfo(SourceFilePath).Length;
                await Vernam.GenerateKeyFileAsync(_keyFilePath, bytesCount, 80_000);

                FileStream inKeyStream = new FileStream(_keyFilePath, FileMode.Open, FileAccess.Read);
                Start(Vernam.Get(inKeyStream));
            }
            catch (Exception e)
            {
                StatusString = "Error: " + e.Message;
            }
        }