Adobe Acrobat 8 3D - Manual (Page 273)

266 ADOBE ACROBAT 3D VERSION 8
User Guide
Note: If you forget a password, there is no way to recover it from the document. It’s a good idea to store passwords in a
separate secure location in case you forget them.
Use A Password To Restrict Editing And Printing Of The Document Restricts access to the PDF file’s security settings.
If the file is opened in Adobe Acrobat, the user can view the file but must enter the specified Permissions password
in order to change the file’s Security and Permissions settings. If the file is opened in Illustrator, Photoshop, or
InDesign, the user must enter the Permissions password, since it is not possible to open the file in a view-only mode.
Permissions Password Specify a password that is required to change the permissions settings. This option is
available only if the previous option is selected.
Printing Allowed Specifies the level of printing that users are allowed for the PDF document.
• None Prevents users from printing the document.
• Low Resolution (150 dpi) Lets users print at no higher than 150-dpi resolution. Printing may be slower because
each page is printed as a bitmap image. This option is available only if the Compatibility option is set to Acrobat 5
(PDF 1.4) or later.
• High Resolution Lets users print at any resolution, directing high-quality vector output to PostScript and other
printers that support advanced high-quality printing features.
Changes Allowed Defines which editing actions are allowed in the PDF document.
• None Prevents users from making any changes to the document that are listed in the Changes Allowed menu,
such as filling in form fields and adding comments.
• Inserting, Deleting, And Rotating Pages Lets users insert, delete, and rotate pages, and create bookmarks and
thumbnails. This option is only available for high (128-bit RC4 or AES) encryption.
• Filling In Form Fields And Signing Existing Signature Fields Lets users fill in forms and add digital signatures.
This option doesn’t allow them to add comments or create form fields. This option is only available for high (128-bit
RC4 or AES) encryption.
• Commenting, Filling In Form Fields, And Signing Existing Signature Fields Lets users add comments and digital
signatures, and fill in forms. This option doesn’t allow users to move page objects or create form fields.
• Page Layout, Filling In Form Fields, And Signing Lets users insert, rotate, or delete pages and create bookmarks or
thumbnail images, fill out forms, and add digital signatures. This option doesn’t allow them to create form fields. This
option is only available for low (40-bit RC4) encryption.
• Any Except Extracting Pages Lets users edit the document, create and fill in form fields, and add comments and
digital signatures.
Enable Copying Of Text, Images, And Other Content Lets users select and copy the contents of a PDF.
Enable Text Access For Screen Reader Devices For The Visually Impaired Lets visually impaired users read the
document with screen readers, but doesn’t allow users to copy or extract the document’s contents. This option is
available only for high (128-bit RC4 or AES) encryption.
Encrypt a PDF and create a recipient list
To encrypt PDFs, you use public-key cryptography. Public-key cryptography uses two keys: a public key, which is
stored inside a certificate that can be shared with other users, and a private key, which you don’t share with others.
The public key (certificate) is used to encrypt documents or to verify digital signatures, and the private key is used
to decrypt documents or to create digital signatures. Both keys are included in a digital ID.