Open XML Application Security (5) Digital signature

To ensure the integrity of the document, prevent the document from being tampered with, and ensure the source of the document, the Open XML provides support for digitally signing the document. The ability to capture digital signatures by using signature lines in Office documents enables organizations to use paperless signing processes for documents such as contracts or other agreements. Unlike paper signatures, digital signatures provide accurate signature records and permit verification of signatures at a later time.

Create a signature

In office, you can digitally sign a document by inserting a signature line. Click Signature line on the Insert tab to see its two options, as shown in Figure 14-28.

Figure 14-28 Signature Line

In Figure 14-28, you see three options, the first two are options to add a signature, and the last one is linked to Microsoft's help page. Click the Microsoft signature line and see the signature settings interface as shown in Figure 14-29.

Figure 14-29 Signature Settings

When you finish setting up the basic information, click OK and you will see a hint about the signature on the right side of the document, as shown in Figure 14-30.

Figure 14-30 Tips for not signing a document

You can right-click the signature and click Sign to see the signing interface as shown in Figure 14-31.

Figure 14-31 Signing the document