Encrypting And Protecting The Contents Of An Excel Spreadsheet

Excel documents often contain sensitive information.  More often, these documents are emailed and uploaded to a variety of locations, many of which are not secure.  Though it’s an easy thing to do, many people either do not know how or simply do not take the necessary time to protect their Excel workbooks before emailing them out.

In addition to password protecting an Excel workbook, you can also limit the types of changes that users can make.  This allows you to protect the data from modification.  I will discuss both encryption and modification protection to Excel documents in the examples below.  Depending on the version of Microsoft Office you are using, the options for encrypting and protecting a workbook may be located in a different place.  For the purposes of this example I will be using Excel 2013.

To access the protection options in Excel, first click File at the top of the screen and then select the Info tab.  On the Info tab click the Protect Workbook button to display the list of available options.

file_info_excel_protect

The first option I will discuss is the ability to encrypt the workbook with a password.  Click this option and you will be prompted to enter a password.

You will need to enter the password twice in order to confirm that it was entered correctly.

excel_enter_password

Once confirmed you will see the Protect Workbook option on the Info tab highlighted to indicate that a password is required to open the workbook.  If you were to close out Excel and then attempt to open the document again you would be promoted to enter the password.

protected_workbook

Another great feature available is the ability to protect the Excel workbook from user’s making certain types of changes.  There are a variety of options that can be selected.

To set up modification protection, go back to the Info page, click the Protect Workbook button again and select Protect Current Sheet.  A window will be displayed giving you a list of options which can be checked to allow the user to perform certain tasks.  If you leave all the options blank the user will be restricted from making any changes.  

protect_worksheet_from_modifications

If you have also encrypted the workbook, it’s best to not use the same password here.  Most users would naturally assume the password is the same and you want the user to be able to view the data but not make any changes.

Finally, one more useful feature is the ability to protect the overall structure of the Excel workbook.  This will prevent users from adding additional worksheets.  To select this option just click the Protect Workbook button again and select Protect Workbook Structure.

protect_workbook_structure

Again, you’ll need to provide a unique password here, just be sure it’s not the same one you used to encrypt the Excel document if you also performed that step.

Once all the options have been configured, save the document and close it.  Try opening it back up and testing to see how these protection features behave.

As previously mentioned, these steps are easy to implement and can provide a relatively secure means to protect sensitive information when being emailed or uploaded over public networks.  Just remember, never email the password alongside the actual document.  It’s best to communicate the password over the phone or, at the very least, in a separate email.