How to make a worksheet Non-Editable even if extension is changed

[Radha Krishnan]

I can make a worksheet non editable by using the worksheet property
objExcelSheet.EnableSelection = XlEnableSelection.xlNoSelection

also i am using the Protect document option with password.
The xls file cannot be able to edit. The document protection is achieved good.

The only problem that i am facing is If the xls file is changed to another
excel file extension say .ods (Open Office Excel document) the protection is
breaked. The password is not retained. The user can just uncheck the Protect
document sheet and can able to edit the document.

How to overcome this issue..

 

[Patrick Molloy]

write your code in C# or VB.Net

The reason for protection is primarily to prevent inadverdent loss of data
through user error. Its not really designed for Security per se. Some might
argue otherwise, but given that its so easy to break - as you've demonstrated
- that you should seek alternative solutions. Perhaps if it's formula you
want to protect, then use code to write the formula, calculate then convert
the results to values. Use VERY Hidden sheets and protect the code. A code
breaker cost $25 last I checked...so security? nope