Create a Digital Signature to a Macro

A digital signature provides assurance that the workbook file is valid and no one has altered it. You can create a personal digital signature by using the Microsoft Selfcert.exe tool. Projects signed with digital signatures created with the Selfcert.exe tool only work on computers that have the certificate in their Personal Certificates store.

Digital signatures that you create with the SelfCert.exe tool work well for personal workbooks; however, if you plan to distribute your workbook to users outside your workgroup, you should consider acquiring a commercial digital signature file. When you use a commercial digital signature file, the digital ID attaches to the macro and remains with it; if anyone alters the macro, Excel notifies the user that someone has changed the macro and therefore the macro should not be trusted.

To view the certificates in your Personal Certificate store, open Internet Explorer. On the Internet Explorer menu, click Tools and then click Internet Options. The Internet Options dialog box appears. Click the Content tab. Click the Certificates button. The Certificates dialog box appears. Click the Personal tab. All of your personal certificates appear.

Create digital signature:

1. Click Start and then click All Programs> Microsoft Office> Microsoft Office Tools> Digital Certificate for VBA Projects.
   The Create Digital Certificate dialog box appears.
2. Type the name you want to give your certificate.
3. Click OK. Excel creates a Personal Digital Certificate.