The following security options are located in the Password Security dialog box:

Compatibility
The compatibility menu contains different levels of encryption, from Version 3 and later with 40-bit encryption (low) to Version 7 and later with 128-bit AES encryption (high). Be aware that version 7 or later is required if only encrypting file attachments.

Be aware that anyone using an earlier version of PDF application/reader cannot open a PDF document with a higher compatibility setting. See Compatibility Controls.

Select Document Components to Encrypt

  • Encrypt all document contents
    Encrypts both the document and the document metadata. The document metadata cannot be searched if this option is selected.
  • Encrypt all document contents except metadata
    The document metadata can be searched with this option selected.
  • Encrypt only file attachments
    A password is required when opening file attachments. However, users can open the document without a password. This option appears only when you select Version 7 and later compatibility.

Allow document opening only by password
Allows you to add a Document Open Password to prevent unauthorized access. This option is unavailable if the Encrypt Only File Attachments option is selected.

  • Document Open Password
    You can specify a password with which the users can open the PDF document. This option appears when Encrypt Only File Attachments is selected.
  • File Attachments Open Password
    You can specify a password with which the users can open the PDF document attachments. This option is available when Encrypt Only File Attachments is selected.

Permissions

  • Set a permissions password to restrict editing of security settings.
    This option allows the following security settings for the PDF document. This option is unavailable if the Encrypt Only File Attachments option is selected.
  • Permissions Password
    Type a password with which a user can change the security settings of the document. The password can also be used to open the PDF document.
  • Printing Permitted
    There are three different printing restriction settings:
    • None. No printing allowed.
    • Low Resolution. Printing must be no higher than 150-dpi resolution. This option is available only if the Compatibility option is set to Version 5 and later, or a higher version.
    • High Resolution. Printing is allowed at any resolution. High-quality vector output to PostScript and other printers with advanced high-quality printing features are practicable.
  • Changes Permitted
    There are five different levels for PDF editing actions:
    • None. No changes allowed to the document.
    • Creating, inserting, deleting, and rotating pages. This allows users to create, insert, delete, and rotate pages. New bookmark and thumbnails are also available. This option is available only if the encryption level is at least Version 5 and later.
    • Filling in form fields and signing signature fields. Allows users to fill in form fields and sign signature fields only. This option is requires at least an encryption level of Version 3 and later.
    • Commenting, filling in form fields, and signing signature fields. This allows commenting, as well as filling in form fields and signing signature fields.
    • Any except extracting pages. This allows any handling of the PDF document listed in the Changes Permitted menu.

Allow copying of text, images, and other content
Allows users to select and copy the contents of the PDF document. Some utilities such as Catalog can also be accessible to the contents. This option is available only if Compatibility is set to at least Version 3 and later.

Allow copying of text, images, and other content and access for the visually impaired
Users can select and copy the contents of the PDF document as well as extract information. Visually impaired users can use screen readers to read the document’s contents. This option  is available only if Compatibility is set to Version 3 or Later.

Allow accessibility (screen readers can access text visually impaired)
This option allows visually impaired users to read the document with screen readers. It is available only if the Compatibility option is set to at least Version 5 and later.

Password Security Options