Digital Signatures in Excel 2007

Add a Digital Signature

What is a digital signature?

A digital signature is another way to protect your Workbook, this is one of the easier protections to break, and all you need to do is remove the signature.

Why should I use it then?

If you need to prove to someone that the document has not been tampered with this will help you. Digital Signatures or Digital Certificates have specific information in them that can be checked to see when it was created.

Differences between Digital Signatures:

If you have not yet created a digital signature, or someone else has not created one for you, there are two types of digital signature that you can create.
     1. Free Digital signature
     2. Paid for Digital Signature

What are the differences?

If you purchase a Digital Signature through a Microsoft Partner, other people will be able to verify that that is your Signature (Certificate).  If you use the free version, others will not be able to verify that you signed the document unless they use the computer that the Signature (Certificate) was created on.

To create a Digital Signature:

     1. Click the Office Symbol Button
      2. Hover over the Prepare Button
      3. Click the Add a Digital Signature
            a. A Dialog Box will appear
            b. Here you can choose if you wish to purchase a Signature (Certificate) or use the free one.
                  i. By clicking the Signature Services from the Office Marketplace… you will be sent to the web and offered several options to purchase one.
                  ii. If you click the OK you can create your own.
      4. After you click OK, you will be offered the choice of purchasing a Digital Signature or Create your
own.
      5. Let us choose Create your own digital  ID
      6. Click OK
      7. Another Dialog box will appear. The  Dialog box will be titled Create a  Dialog ID.
      8. Fill in the information that you want to see when you  look at the Digital Signature (Certificate).
      9. Click the Create Button.
      10. You will be asked to create a purpose for signing. You can use  any reason that you wish.
      11. Then Click the Sign Button.
      12. You will then see a  confirmation dialog. If you do not  wish to see this dialog after you  sign another document just check  the setting Don’t show this  message again.
      13. Hit okay, this dialog box  will disappear, and another dialog  box will appear
      14. A signature validation dialog will show at the right side of  the spreadsheet and it will show the name of the  signature.
            a. You can hide the signature box by clicking the X in  the right hand corner.
            b. In the status bar at the bottom of the Workbook  you will see a symbol that  indicates the  Workbook has been  digitally signed.
            c. If the Valid signature dialog box has been closed you can reopen it by double clicking this icon. There is another way to open the dialog box by clicking the office symbol, going to the prepare selection and clicking the View Signatures button.
      15. The Digital Signature will do two things for you.
            a. It will sign the Workbook.
            b. It will automatically mark the Workbook as Read Only. Read Only means that others  cannot change any content within the Workbook.