Public Class MyData
   Private fInfo As IO.FileInfo
 
   Public Sub New(ByVal fi As IO.FileInfo)
      fInfo = fi
   End Sub
 
   Public Function GetFileInfo() As IO.FileInfo
      Return fInfo
   End Function
 
   Public Sub EncryptData()
      ' MemoryStream erstellen und Original-Daten in den Stream schreiben
      Dim oStream As New IO.MemoryStream
      With New IO.StreamWriter(oStream)
         .Write(GetFileInfo.OpenText.ReadToEnd)
         .Close()
      End With
 
      ' Daten verschlüsseln
      Dim bData() As Byte
      bData = ProtectedData.Protect(oStream.ToArray(), Nothing, _
        DataProtectionScope.CurrentUser)
 
      ' verschlüsselte Daten in Datei speichern
      GetFileInfo.OpenWrite.Write(bData, 0, bData.Length)
   End Sub
 
   Public Sub DecryptData()
      ' Datei mit verschlüsselten Daten auslesen
      Dim bData(-1) As Byte
      GetFileInfo.OpenRead.Read(bData, 0, GetFileInfo.Length)
 
      ' Daten entschlüsseln
      bData = ProtectedData.Unprotect(bData, Nothing, _
        DataProtectionScope.CurrentUser)
 
      ' in String umwandeln und in Datei schreiben
      Dim oStream As New IO.MemoryStream(bData)
      With New IO.StreamReader(oStream)
         GetFileInfo.CreateText.Write(.ReadToEnd)
         .Close()
      End With
   End Sub
End Class