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.
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Secure This Document |
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.
Confirm document open

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Apply digital ID |
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.
Final digital signature
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.
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