Normally, you sign a (paper) check to authenticate its validity to the recipient (and, in due course, to your bank). Similarly, you can apply a digital signature to a Word document to authenticate its validity.
A digital signature is a mathematical scheme for demonstrating the authenticity of a digital message or document. A valid digital signature gives a recipient reason to believe that the message was created by a known sender, and that it was not altered in transit. Digital signatures are commonly used for software distribution, financial transactions, and in other cases where it is important to detect forgery or tampering.
Digital signatures can be used to authenticate the source of messages. When ownership of a digital signature secret key is bound to a specific user, a valid signature shows that the message was sent by that user. The importance of high confidence in sender authenticity is especially obvious in a financial context.
The following article will explain you how to apply a Digital Signature to the word document.
To apply a digital signature to a document, follow these steps:
- Finalize the document, and save any unsaved changes to it.
- Click the Office Button, click or highlight Prepare, and then click Add A Digital Signature. Word displays the Sign dialog box, shown here.
- In the Purpose For Signing This Document text box, type a description of why you’re signing the document.
- If your computer has two or more digital IDs installed, and the Signing As group box shows the wrong signature, click the Change button, choose the correct certificate in the Select Certificate dialog box, and then click the OK button.
- Click the Sign button. Word closes the Sign dialog box, applies the digital signature, and then displays the Signature Confirmation message box, shown here, warning you that changing the document will render your signature invalid.
- Select the Don’t Show This Message Again check box if you can dispense with this message box in future, and then click the OK button. Word closes the message box and displays the Signatures pane, shown here.
- Close the document. (You don’t need to save changes—Word has already saved them for you.)
Although messages may often include information about the entity sending a message, that information may not be accurate.
A digital ID you create yourself via the Create A Digital ID dialog box is useful only for testing. It has no authentication and is worthless in the real world.