Protecting an Excel file published on web from unauthorized copying

[kvin]

Is there a way protect an Excel file (and associated formulas) which is
published on web from unauthorized copying and/or create time limited
functionality? Perhaps, converting excel into flash?

thanks.

 

[Guest]

Short answer: you put it on the web in such a manner that I can download it,
and there's no stopping me then! If you password protect it, I'll crack the
passwords in the amount of time it takes me to bring up a program I have
designed to do exactly that and point it to the file I've downloaded. Once
it's open, I have pretty much free rein to do what I want. Even if you try
to time limit the functionality via code, I can stop the code from running -
I may not have access to your functions and macros at that point IF you've
locked up the VBA project with a password, but I think I can get around that
also (haven't tried, but I have the methodoligy in mind - may or may not
require cracking password to the VBA project which is tougher to do than
cracking the workbook or worksheet password(s) -- but again, there are tools).

I've never considered trying to convert Excel to Flash - no expertise in
that at all, I suppose it could be done?

If you don't need any inter-action between viewers and the workbook, you
might consider converting it to an Adobe .pdf file, you can assign
limitations on what can be done to those if you use Adobe Acrobat Pro (a few
hundred $$). Or consider just taking screen shots of the sheet(s) if you can
get it all on a screen to shoot it, and just posting the .jpg or .gif file
you create doing that?

 

[kvin]

Short answer: you put it on the web in such a manner that I can download it,
and there's no stopping me then! If you password protect it, I'll crack the
passwords in the amount of time it takes me to bring up a program I have
designed to do exactly that and point it to the file I've downloaded. Once
it's open, I have pretty much free rein to do what I want. Even if you try
to time limit the functionality via code, I can stop the code from running -
I may not have access to your functions and macros at that point IF you've
locked up the VBA project with a password, but I think I can get around that
also (haven't tried, but I have the methodoligy in mind - may or may not
require cracking password to the VBA project which is tougher to do than
cracking the workbook or worksheet password(s) -- but again, there are tools).

I've never considered trying to convert Excel to Flash - no expertise in
that at all, I suppose it could be done?

If you don't need any inter-action between viewers and the workbook, you
might consider converting it to an Adobe .pdf file, you can assign
limitations on what can be done to those if you use Adobe Acrobat Pro (a few
hundred $$). Or consider just taking screen shots of the sheet(s) if you can
get it all on a screen to shoot it, and just posting the .jpg or .gif file
you create doing that?

-----------

one person just asked me is there a way to prevent
downloading(copying/distributing) an .xls file placed on web. Since I am not
excel expert, i just wanted ask some advice. I personally consider that this
is very difficult, if not possible at all. One of the way I see is convert
Excel spreadsheets into html web pages with embedded JavaScript. This html
pages will look and function in the same way as the original spreadsheet.
Then I can encrypt html page with some html protector program, that makes
the decryption very disgusting and hard procedure, so no anyone want to be
caught doing decoding.. This way even is someone will download page it would
not be a problem. The only question is how big is this original xls
spreadsheet, since converting to html add many extra code.