Security - Delete File

[Anthony]

Hi,

I have a file created in Excel, and I have been asked to secure it in some
way to stop staff from copying the file and taking it home.

I know I can password it, which is a start but I was wondering if it is
possible to have Excel, using VBA code, look at the machine id and if it
isn't "XYZ" have it delete itself.

I have no idea if this is at all possible as I am not very literate in VBA
Code.

Any Help/Suggesstions would be greatly appreciated.

Thanks in advance,
Anthony.

 

[Tom Ogilvy]

Copying a file is a Windows activity. It has nothing to do with Excel. You
can just go to windows Explorer and copy the file. If you password protect
it, then at least if they copy it, they can not get into it easily although
there are password cracker programs that can defeat the file password. (but
if they use the file at work, wouldn't they need to know the password?).

You might want to put key information in a database and have the file query
that database to get the information. Set it up so the information is not
stored in the file. Any approach is not going to be foolproof, so what
measures you take would depend on how sensitive the information is.

Perhaps you can put the file on a single stand alone computer and control
access to the computer. If you don't want it copied, controlling access to
the file would be the most robust.

 

[Anthony]

Thanks for your reply Tom,

This file is actually a POS program, written in Excel with a lot of
formulas, it holds sheets with a lot of costings and sensetive information,
but holds no actual data, it is used to create an invoice.

All the sheets with the sensetive info are hidden, and all the formulas are
hidden, and password protected.

So the actual file is usable with out needing a file password, but in order
to change the formuals/pricing a password is required(which the programmer
has).

But as I am aware that password crack programs are quite easily available, I
dreamt up the idea that maybe it would be possible to write into code (maybe
in an Autoexex, if it exists) something where it looks at the machine ID
when the workbook is opened, and if it is not a specific machine name(hard
written into the code) the code could delete the workbook or certain sheets
within the workbook, this way if a staff member were to copy the file and
take it home, it would not funtion correctly as their computer name would be
different to the one hard coded into the Module.

I know no system is fool proof, but thought this, if possible, could help.

Should I stop dreaming, and just run with password protection?

 

[Tom Ogilvy]

any code based solution is easily defeated by disabling macros before
opening the file.

Sheet protection is very week. Free code or links to free code to break
this protection is posted almost daily.

 

[Guest]

you could write an external procedure and then access it when the sheet is
opened. the proc would then shut down excel it the current machine is not the
desired machine...