Hands on: Keep your spreadsheets private

There are all sorts of ways you can restrict access to your Excel files, worksheets or even ranges and cells. You may have reasons ranging from wishing to conceal confidential information from others to simply preventing yourself from inadvertently deleting a complicated formula.

A quick way to hide data in a cell is to format the displayed value in the cell in the same colour as the background. The most drastic step is to not allow anyone to open a workbook at all without a password.

The simplest way to do this is by opening the file and choosing Save As, Excel Workbook, and clicking the Tools down arrow. Choose General Options. In this dialogue box, you can enter a password that permits the file to be opened and another that allows the file to be modified. These passwords are case-sensitive, so ‘DrIMrP’ is different from ‘DriMRp’.

An alternative would be to personalise permissions. In other words, you can specify who can and can’t use your workbook. Microsoft helps you to do this with a service called Information Rights Management, or IRM for short.

Passport to Excel
If you have a Hotmail email account, you can use that address and password. If not, get a Microsoft Passport for your regular email address. Next, connect to the internet and in Excel 2007, under the Review tab, click the down arrow by Protect Workbook and choose Restricted Access.

The first time you do this you will be offered the chance to download and install a small Office update file –­ and you can also sign up for Microsoft’s free IRM service.

After that, when you choose Restricted Access for an open workbook, you can enter the email addresses of those who are permitted to read the workbook but not change, print or copy the content. Separately, you can enter the email addresses of those who can read, edit and save changes but not print the workbook.

There are a number of other options you can specify for each user, such as allowing some people to print the workbook and setting a date when individual permissions are withdrawn.

Anyone who wants to open the workbook has to supply their email address and password, connect to the IRM service, and find out what permissions they have. They also have to download the IRM add-in once, if it’s not installed on their computer.