protecting an empty workbook

[Juggernath]

I'm working in academic institution - to prevent cheating when students have
to solve their homework problem, I think of sime kind protection.
I would like to get an ID from hard disc of the student, then lock empty
book for editing to anyone except the computer with that hard disc and me.
Also, I'd like to prevent copy/paste from another workbook.
Any ideas, how to override disabling macros, how to get hard disc ID etc...

 

[Francois via OfficeKB.com]

I'm working in academic institution - to prevent cheating when students have
to solve their homework problem, I think of sime kind protection.
I would like to get an ID from hard disc of the student, then lock empty
book for editing to anyone except the computer with that hard disc and me.
Also, I'd like to prevent copy/paste from another workbook.
Any ideas, how to override disabling macros, how to get hard disc ID etc...

I would think that your students would soon be able to crack any method you
use to set ID etc.

Security is not one of Excels good points.

 

[JE McGimpsey]

If your workbook can be opened, all internal protection is trivial to
bypass:

http://www.mcgimpsey.com/excel/removepwords.html

and

http://www.mcgimpsey.com/excel/fileandvbapwords.html

Unless your academic institution is an elementary school (and I'm not
particularly confident about that age group), XL is not a platform that
can be configured to prevent cheating by even moderately motivated
students.

 

[Juggernath]

I would think that your students would soon be able to crack any method
you
use to set ID etc.

Security is not one of Excels good points.

Thanks, I know that protecting a workbook isn't great idea, but, students
should solve their problems creating their workbooks. So if someone does job
for them, there is possibility to read from disc, not to protect, but, at
least to put information of hard disc ID somewhere in the workbook to be
sure that it's made on students machine.
To be more specific, it will be quite easy to identify computer of the
cheater, because there is one person that does all homeworks for money.
Maybe this "silent" approach would be better? Any ideas?

 

[JE McGimpsey]

Thanks, I know that protecting a workbook isn't great idea, but, students
should solve their problems creating their workbooks. So if someone does job
for them, there is possibility to read from disc, not to protect, but, at
least to put information of hard disc ID somewhere in the workbook to be
sure that it's made on students machine.
To be more specific, it will be quite easy to identify computer of the
cheater, because there is one person that does all homeworks for money.
Maybe this "silent" approach would be better? Any ideas?

Even if such a scheme could be implemented securely, with remote desktop
software, it would be trivial for such a cheater to create/edit
workbooks on the student's machine.

 

[Juggernath]

Even if such a scheme could be implemented securely, with remote desktop
software, it would be trivial for such a cheater to create/edit
workbooks on the student's machine.

LOL, i think he is not that lucid
What I'm thinking at this moment is to chrash MSExcel when one tries to
access macros, is it possible? I never heard of something like that, but,
maybi it could work. Then I can do whole bunch of macros to protect from
copy/paste etc.
The cheater has a template, and I'm quite sure that he wouldnt have a time
to put all the formulas etc. to worksheet without copy/paste

 

[JE McGimpsey]

LOL, i think he is not that lucid

If he's *really* not that lucid, then perhaps embedding a hidden name
would work. For instance, create your own template workbook, with the
student name in, say, cell A1 (and perhaps some boilerplate elsewhere to
make it look more legitimate). Then run this macro (from another
workbook - perhaps your Personal.xls workbook) for each student, saving
the workbook with their name A1 and embedded in the filename:

Public Sub InsertHiddenName()
ActiveWorkbook.Names.Add _
Name:="StudentName", _
RefersTo:=Sheet1.Cells(1, 1).Text, _
Visible:=False
End Sub

Send each student their own personal template and insist that they use
it for their homework. Now, if the cheater copies his own template and
changes the student name in A1 (and the filename), his hidden name will
still be there, which you can read in the immediate window with

Debug.Print ActiveWorkbook.Names("StudentName").RefersTo

Again, this is rather trivial for any sufficiently suspicious person to
find and work around, but it may trip up the ignorant.

What I'm thinking at this moment is to chrash MSExcel when one tries to
access macros, is it possible? I never heard of something like that, but,
maybi it could work.

As far as I know, it's not possible.

Then I can do whole bunch of macros to protect from
copy/paste etc.

That would prevent the legitimate students from using copy/paste, too,
right?

And your cheater could bypass any of your macros by opening the file
with macros disabled.

The cheater has a template, and I'm quite sure that he wouldnt have a time
to put all the formulas etc. to worksheet without copy/paste

Perhaps someone else can come up with something else, but if your
cheater is even moderately familiar with VBA, he'll be able to bypass or
work around everything you can throw at him.

 

[Juggernath]

That would prevent the legitimate students from using copy/paste, too,
right?

Yes, I think, dragging the formulas inside the worksheet is enough for this
kind of problems.

Perhaps someone else can come up with something else, but if your
cheater is even moderately familiar with VBA, he'll be able to bypass or
work around everything you can throw at him.

He's not familiar with VBA, fortunatelly .

Thanks for the answers