Excel® 2013 On Demand

Adding a Digital Signature

After you’ve finished a workbook, you might consider adding an invisible digital signature—an electronic, secure stamp of authentication on a workbook. Before you can add a digital signature, you need to get a digital ID, or digital certificate, which provides an electronic way to prove your identity. A digital certificate checks a public key to validate a private key associated with a digital signature. To assure a digital signature is authentic, it must have a valid (non expired or revoked) certificate issued by a reputable certification authority (CA), and the signing person must be from a trusted publisher. However, a verified certified digital ID is not always needed. If you don’t need a verified digital certificate, ...