Microsoft Office Tutorials and References
In Depth Information
Concerning Yourself with the End User
h Hide the formulas in specific cells: You can hide the formulas in specific cells (by using
the Protection tab in the Format Cells dialog box) so that others can’t see them. Again,
hiding takes effect only when the document is protected by choosing the
Review ➜ Changes ➜ Protect Sheet command.
h Protect an entire workbook: You can protect an entire workbook — the structure of the
workbook, the window position and size, or both. Use the Review ➜ Changes ➜ Protect
Workbook command for this purpose.
h Lock objects on the worksheet: Use the Properties tab in the Size and Properties dialog
box to lock objects (such as shapes) and prevent them from being moved or changed. To
access the Size and Properties dialog box, select the object and then click the dialog box
launcher in the Drawing Tools ➜ Format ➜ Size group. (This context tab appears only when
an object is selected.) Locking objects takes effect only when the document is protected
via the Review ➜ Changes ➜ Protect Sheet command. By default, all objects are locked.
h Hide rows, columns, sheets, and documents: You can hide rows, columns, sheets, and
entire workbooks. Doing so helps prevent the worksheet from looking cluttered and also
provides some modest protection against prying eyes.
h Designate an Excel workbook as read-only recommended: You can designate an Excel
workbook as read-only recommended (and use a password) to ensure that the file can’t
be overwritten with any changes. You do this designation in the General Options dialog
box. Display this dialog box by choosing File ➜ Save As. In the Save As dialog box, click
the Tools button and choose General Options.
h Assign a password: You can assign a password to prevent unauthorized users from
opening your file. Choose File ➜ Info ➜ Protect Workbook ➜ Encrypt With Password.
h Use a password-protected add-in: You can use a password-protected add-in, which
doesn’t allow the user to change anything on its worksheets.
How secure are Excel’s passwords?
As far as I know, Microsoft has never advertised Excel as a secure program. And for good
reason: Circumventing Excel’s password system is actually quite easy to do. Several commercial
programs are available that can break passwords. Excel 2002 and later versions seem to have
stronger security than previous versions, but a determined user can still crack them. Bottom
line? Don’t think of password protection as foolproof. Sure, it will be effective for the casual user.
But if someone really wants to break your password, he can probably do so.