Save Mode: Full or Cell Values

If you let users save their changes made to your Excel workbook, you have to define the way XLS Padlock will store (and restore) these changes.

The XLS Padlock software offers  two different saving modes:

•Save full workbook (.XLSC file)

•Save defined cell values only (.XLSCE file)

The mode can be selected on the Workbook Saving/Loading page. Let's review them:

Save full workbook (.XLSC file)

A full copy of the workbook with changes made by your customers will be securely stored in a file at the location specified by them. This file is given the extension .XLSC (this can be customized) and can’t be opened without running the compiled workbook again. Thus, your workbook remains safe. Excel itself is unable to recognize the .XLSC proprietary format.

The Full Save mode encrypts and saves the entire workbook exactly as it is at the moment of the user's save. So, if an end user modifies their workbook, saves it and then you distribute a new EXE with updates, when the user opens their previous save file, they will retrieve their modifications, not your updates. This is because their saved file is an exact snapshot of the workbook at the time of the save. Your updates will be in the compiled workbook embedded in the new EXE, but not in the end user's saved file.

Full save files can be shared between users (unless you decide to lock them to a particular machine). It is even quite possible for customers to send you their save files, so that you can decrypt them and reuse data provided by your customers.

Again, these save files can only be opened by your application and not from someone's else: this is possible because XLS Padlock uses a unique secret key (that you will have defined as explained here) to generate save files specific to each application. So, another user of XLS Padlock will not be able to open your save files unless he has the secret key (though, of course, you will not reveal it to anyone).

The main drawback of this saving mode is that, when you deploy an updated EXE file, XLSC save files made previously by customers won’t be automatically upgraded. Instead, customers will see the last changes they made and not yours. That’s the expected behavior since we restore the full workbook saved by the customer. In that situation, you can rely on the second saving mode as explained below.

Save defined cell values only (.XLSCE file)

With this save mode selected, only the values of certain cells that you defined before compiling the workbook will be kept and restored when a save file is loaded.

Thus, if you frequently modify your source workbook and distribute these new versions to your customers, they will benefit from the updates while having the possibility to reload the values of the cells they themselves have modified.

The main disadvantage is that you have to tell XLS Padlock which cells you want your customers to be able to save. This must be done before compiling and distributing your application thanks to the Excel's context menu command named "Let users save and restore selected cell value(s) with XLS Padlock".

When customers click the Excel's Save button, the application will read all specified cells and store their values securely in a file at the location specified by them. This file is given the extension .XLSCE (this can be customized except the final E letter) and can’t be opened without running the compiled workbook again. Thus, even in this specific save mode, your workbook remains safe. Excel itself is also unable to recognize the .XLSCE proprietary format.

It is moreover possible for customers to send you their save files, so that you can decrypt them and load cell values saved by your customers into the currently loaded Excel workbook.

Finally, these XLSCE save files can only be opened by your application and not from someone's else, since XLS Padlock uses a unique secret key (that you will have defined as explained here) to generate save files specific to each application. So, another user of XLS Padlock will not be able to open your save files unless he has the secret key (though, of course, you will not reveal it to anyone).