Saving and DRM

[Guest]

Is it possible to save an Excel spreadsheet with some kind of DRM? I am
wanting to allow changes to be saved to a file, but I do not want the file to
be saved to any other medium. I would also like to be able to allow one or
two saves to another medium.

 

[hrlngrv]

LDanix wrote...

Is it possible to save an Excel spreadsheet with some kind of DRM? I am
wanting to allow changes to be saved to a file, but I do not want the file to
be saved to any other medium. I would also like to be able to allow one or
two saves to another medium.

Not without cooperation from the OS, and not without embedding
information about the medium on which the file is stored. Note that
such a scheme could render the file unusable if the disk in question
crashed and had to be restored from backups onto a new disk.

In theory there's some sort of lightweight DRM provided by Excel 2003
for files stored on Windows Server 2003, but I don't believe it
prevents copying. Given the relative ease with which music CDs and
movie DVDs can be ripped, it's unwise to believe that ordinary computer
files would be any safer against determined attack.