In the third of several PDF security articles, we show you how to sign a PDF file with your digital signature.In our
last article, we explained how to create a digital ID. In this lesson, we'll sign your PDF file with that digital ID.
1. Click the Sign button on the toolbar, and choose Sign This Document from the menu. Acrobat first reminds you that this document is not certified. (You'll certify a document later in this lesson.)
2. Click Continue Signing. Now Acrobat reminds you that you need to create a signature field.
Note: When you certify a document, you attest to its contents and specify the type of changes that a user can make to the document without invalidating the signature. When you sign a document, any subsequent changes to the document affect the validity of the signature.
Because you want the department or agency receiving your PDF file to know that the changes to this PDF are approved and you want them to be sure that no additional changes have been made since the time you approved it, you'll create a visible signature field and sign the document. In a subsequent lesson you'll certify a document.
Any time you add a first signature to a document, you should consider certifying the document when prompted.
3. Make sure that the Create a New Signature Field to Sign option is selected, and click Next.
4. Click OK to close the alert box, and drag to create a signature field. We dragged a signature field in the area below the headline. You may establish multiple identities, depending on your needs. If you have not established any identities except T. Simpson (the faux identity we created in the last article), skip Step 5.
5. If you have any other identities defined, other than T. Simpson, you're asked to select your identity. Select the Digital ID that you just created, and click OK. We selected T. Simpson, Director.
6. In the dialog box, enter your password. We entered Lotion123.
7. Choose a reason for signing the document. We chose I Am Approving This Document from the drop-down menu. (See Figure One.)
Before you complete the signature process, you'll change the appearance of your signature.
Next Page: Adding an image to the signature.
Adding an image to a digital signature
1. Click the Show Options button to display the signature appearance options.
2. Click the New button to open the Configure Signature Appearance dialog box where you can modify your signature's appearance.
The Preview pane shows the default digital signature appearance. First you'll name your signature and then add your corporate logo to the signature block.
3. In the Title text box, enter a name for your signature. We entered Logo because we're going to add our corporate logo to the signature line. You should use a name that is easy to associate with the contents of the signature.
4. In the Configure Graphic section of the dialog box, select the Imported Graphic option and click the File button.
5. In the Select Picture dialog box, click the Browse button and locate your company logo (or any other image you'd like to use for this article's training purposes). Supported file types are listed in the Files of Type (Windows) or Format (Mac OS) menu. Click Select, and then click OK to return to the Configure Signature Appearance dialog box.
Now you'll specify the information to be included in the text block of your signature. You'll include your name, the reason for signing the document, and the date.
6. In the Configure Text area of the Configure Signature Appearance dialog box, leave Name, Date and Reason selected. Deselect all the other options. (See Figure Two.)
7. When you're happy with the preview of your signature block, click OK.
8. Click Sign and Save in the Apply Signature to Document dialog box to apply the signature. Click OK to close the alert box.
The recipient of the signed document needs your signer's certificate to validate the digital signature.
In our next article, we'll show you how to modify a signed document. In subsequent articles, we'll demonstrate how to certify a PDF file, and then explore security settings and how to add different types of security to a PDF.
Pages 347-351 excerpted from "Adobe Acrobat 7.0 Classroom in a Book." Copyright © 2005. Used with the permission of Pearson Education Inc. and Peachpit.
Document Management 
