Adobe Acrobat 9 PRO Extended - Manual (Page 272)

266 USING ACROBAT 9 PRO EXTENDED
Digital signatures
Last updated 9/30/2011
Sign in Preview Document mode
For best results, use the Preview Document feature when you sign documents. This feature analyzes the document for
content that may alter the appearance of the document. It then suppresses that content, allowing you to view and sign
the document in a static and secure state.
The Preview Document feature can help you find out if the document contains any dynamic content or external
dependencies. It can also help you find out if the document contains any constructs such as form fields, multimedia,
or JavaScript that could affect its appearance. After reviewing the report, you can contact the author of the document
about the problems listed in the report.
You can also use Preview Document mode outside a signing workflow to check the integrity of a document.
Sign a PDF in Preview Document mode
1 Open the Preferences dialog box, and select Security on the left.
2 Select View Documents In Preview Document Mode When Signing, and click OK.
3 In the PDF, click the signature field, or click the Sign button in the Tasks toolbar and choose Sign Document.
The document message bar appears with the compliance status and options.
4 (Optional) Click View Report in the document message bar (if available) and select each item in the list to show
details. When you’re done, close the PDF Signature Report dialog box.
5 If you’re satisfied with the compliance status of the document, click Sign Document in the document message bar,
and add your digital signature.
6 Save the PDF using a different name than the original, and close the document without making any further changes.
Before you certify a PDF
Document authors can improve document integrity and ensure that their documents remain certified by addressing
the following issues before they certify PDFs:
• Disable or remove content that could modify the document or compromise its integrity, such as JavaScripts,
actions, or embedded media.
• If you intend for others to sign the document using Adobe Reader, enable usage rights to let Adobe Reader users
add a digital signature (choose Advanced > Extend Features In Adobe Reader).
• Certify or sign a PDF only after you make final changes to it. If you make changes or resave the PDF after you sign
it, you may compromise the validity of your signature or the document’s certified status.
Document authors can use Adobe LiveCycle Designer (Windows) to create signature fields that lock after signing,
preventing changes that may invalidate signatures. For more information, see Adobe LiveCycle Designer Help.
Acrobat Forms authors can use the option with a signature field to specify which fields should lock after signing.
More Help topics
“ Examine a PDF for hidden content ” on page 255