password protected sheet

[farnye]

I am creating some excel sheets for work and need to password protect them all. However I know there will be some people that will attempt to hack the file.

Is there a way that I can open the spreadsheet and see if someone has turned ever off the protection.....(I am assuming that they turned it off, made their changes, and turned it back on.)

 

[handleman]

I think you would have to do it with a macro. The macro could be set to trigger on any of the sheet or workbook events and either make some small change somewhere that the hacker may or may not notice, or delete the whole sheet, reformat his hard drive, etc.

 

[IRstuff]

There are various flags that are set when the file is protected:

If ActiveWorkbook.ProtectStructure = True Then
MsgBox "Remember, you cannot delete, add, or change " & _
Chr(13) & _
"the location of any sheets in this workbook."
End If

These are described in the help files. One thing that you can do to make it more difficult for the thief is to remove all the copy and save commands from the menus and toolbars in your sheet. You can also reassign the copy or save commands to run a macro that makes a permanent change or emails you or whatever.

TTFN

FAQ731-376

 

[joerd]

There is one thing about cracking passwords in Excel: you aren't going to find the original password, only one that gives the same "hash". So, if the workbook is no longer protected with your password, it has been opened and saved by someone else. Then again, you might never see the cracked copy, so you would need another method as suggested above.

Cheers,
Joerd

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.

 

[farnye]

Thanks for the advice. Would there be a better way to secure the file other than using excel's password?

 

[Ashereng]

If I wanted to hack a file, I would make a copy first. This way, I can hack at my leisure, and the originator wouldn't be bothered.

If you need to truely secure a file, Excel's password is not going to do it. I am not a security expert, so I would recommend you consult one if "security" is a real concern.

"Do not worry about your problems with mathematics, I assure you mine are far greater."
Albert Einstein
Have you read FAQ731-376 to make the best use of Eng-Tips Forums?

 

[IRstuff]

If the items to be secured are calculations, you have the possibility of creating an add-in to do the calculation, which is obviously quite involved. Nonetheless, such an approach is portable and makes the protection much more inherent and robust.

TTFN

FAQ731-376

 

[johnwm]

Excel password security is almost totally ineffective to any even slightly determined user. There are free/cheap crackers available everywhere. If you have concerns over Excel security there is a overview at

http://www.codematic.net/Excel-development/Excel-dev-general/excel-security.htm

You can also use COM addins/XLLs for your calculations if you want to keep meddlers out - a quick google for 'xll microsoft' will take you to several info sources and examlpes

Good Luck
johnwm
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[sdz]

There are excel compilers avalable. Try putting "excel compiler" into a search engine. Here's one but I make no recommendations

http://www.gold-software.com/download9409.html