Securing PDF Documents in Acrobat 3D

Create a digital signature and password protect your PDFs

Acrobat 3D provides several options to secure your PDF documents, with several layers of security within those options. These options include password protection, digital signatures, and for corporate and government environments, server managed security via Adobe’s LiveCycle Policy Server software. Within this tutorial we’ll create a secure PDF document and take a look at the options available with the password protection and the digital signature security options.

When you have finished creating your PDF and are ready to protect that document, you can start the security process. Have the PDF document open in Acrobat 3D and select Document>Security>Secure this Document. The Select a Policy to Apply window opens. Your choices here include Encrypt for Certain Identities Using Certificates, which enables you to apply certificate security to the PDF, or Restrict Opening and Editing Using Passwords, which gives the PDF password security. 

 Select Password Security. The Password Security Settings window will open. Here you determine what compatibility you wish the PDF to maintain. You can choose to give compatibility to those using Acrobat 3 or 5 or later, Acrobat 6 or later, or Acrobat 7 or later.

For the widest compatibility, choose Acrobat 3 or later. For the least compatibility, choose Acrobat 7 or later. While choosing Acrobat 3 or later will encrypt all the contents in the PDF, choosing Acrobat 6 or later will also encrypt all the document contents except the metadata, while choosing Acrobat 7 or later will add file attachments, if any, to the document components slated for encryption.

Choose the format you wish to encrypt to as well as any document components, and then check the box Require a password to open the document. You also set permissions in the Password Security Settings window. Permissions restrict the capability to edit and print the document. If you wish to give the user permission to make changes to the PDF, you must give a new password in the password field in order to do so.

You can give the recipient permission to print the document at low resolution 150dpi, high resolution, or not at all. In addition, you can give the user permission to insert, delete, and rotate pages within the PDF, the capability to fill in form fields and sign existing signature fields, commenting, filling in form fields and signing existing signature fields, and any except extracting pages from the document. You can also choose to give the user the capability to copy text, images and any other content within the PDF, and enable text access for screen reader devices for the visually impaired.

Click OK. Acrobat 3D will open a screen asking you to confirm the document open password. Type it in. You will get a warning box stating that some third party applications may be able to bypass some restrictions. Click OK.

You will then confirm the permissions password. Type it in. That is it. When the recipient receives the password protected PDF document and tries to open it, a password window will pop up asking for the password. When the recipient types in the password, the PDF document will open.

The Digital Signature is another option to PDF document security. Without a digital signature, anyone can alter the original document without the author’s consent. With Digital Signature you have two options. You can create a regular Digital Signature or a Certifying signature. If unauthorized changes are made to a PDF when the document is certified, the certifying signature becomes invalid.

When you sign a regular digital signature, you have the choice of creating a new signature field to sign or creating an invisible signature. Select Create New Signature as the document does not yet have a signature. Acrobat 3D will ask you to select the area of the PDF where you wish the signature to reside. After you selected the area with your pointing device, a new window called Apply Digital Signature opens.

 If you haven’t yet created a digital ID, do so now by selecting Add Digital ID. Select Create a Self-Signed ID. You will then have two options, add new PKCS#12 Digital ID file, or Windows Certificate Store. The PKCS#12 format is supported by most security software applications while Windows Certificate Store is supported by most Windows applications. The choice is yours. For this tutorial I chose Windows Certificate Store. 

In the next window you will fill out the pertinent signature information, the key algorithm encryption (1024-bit RSA or 2048-bit RSA), as well as the digital ID permissions (digital signatures and data encryption, digital signatures, or data encryption). You can also choose to enable unicode support.  Click finish and the ID is created, to which you can now apply to your PDF documents. When you apply the digital signature to your documents, you can select why you are signing the document or select none. Your signature will appear in the place on the PDF designated by you with all pertinent information.