You can limit access to PDF documents by setting passwords and by restricting certain features, such as printing and editing. When a PDF document has restricted features, tools and menu items that are related to those features are dimmed. You can also use other methods to create secure documents, such as encrypting or certifying a document. A security setting contains the password and specific options to use for certain PDF conversions.
On the Security Settings page, you can do the following tasks:
A security setting controls the security and permissions for files that are converted with that security setting.
These settings configure the compatibility and encryption. For instructions about accessing the fonts settings, see Create or edit a security setting.
Sets the type of encryption for opening a password-protected document. The Acrobat 3.0 And Later option uses a low encryption level, but the other options use a high encryption level:
Acrobat 9.0 And Later:
Uses high encryption (256-bit AES). This option lets you enable metadata for searching and encrypt only file attachments.
An earlier version of Acrobat cannot open a PDF document that has a higher compatibility setting. For example, if you select the Acrobat 7.0 And Later option, you cannot open the document in Acrobat 6.0 or earlier.
Ensure that the compatibility level is consistent with the PDF compatibility level for the same source. For example, if you have a watched folder configured to use the Standard PDF setting, which is compatible with Acrobat 5.0 or later, your security compatibility level must not be higher than Acrobat 5.0.
The document restrictions that are available depend on the Compatibility option you selected.
Encrypt All Document Contents Except Metadata (Acrobat 6 And Later Compatible):
Encrypts the contents of a document but still allows search engines to access the document metadata. This option is available only when the Compatibility option is set to Acrobat 6.0 or later, Acrobat 7.0 or later, or Acrobat 9.0 or later.
Encrypt Only File Attachments (Acrobat 7 And Later Compatible):
Users can open the document without a password but must enter a password to open file attachments. This option is available only when the Compatibility option is set to Acrobat 7.0 or later or to Acrobat 9.0 or later.
These settings configure the password security:
Note: If you forget a password, it cannot be recovered from the document. It is recommended that you store passwords in another secure location in case you forget them. Also, keep a backup copy of the document that is not password-protected.
Document Open Password:
Prevents users from opening the document unless they type the password you specify. Passwords are case sensitive. Acrobat uses the RC4 method of security from RSA Security Inc. to password-protect PDF documents. If you are restricting printing and editing, it is recommended that you add a document open password to enhance security.
Require A Password To Open File Attachments:
Enables the password options. This option is available only when the Compatibility option is set to Acrobat 7.0 or later or to Acrobat 9.0 or later, and the Document restriction option is set to Encrypt Only File Attachments.
File Attachment Open Password:
Ensures that a password is required to open a file attachment. Users can open the document without a password. This option is available only when the Compatibility option is set to Acrobat 7.0 or later or to Acrobat 9.0 or later, and the Document restriction option is set to Encrypt Only File Attachments.
Retype File Attachment:
Ensures that the password is correct. This option is available only when the Compatibility option is set to Acrobat 7.0 or later or to Acrobat 9.0 or later, and the Document restriction option is set to Encrypt Only File Attachments.
These options configure the permissions:
Use A Password To Restrict Printing And Editing Of The Document And Its Security Settings:
Enables restrictions on permissions.
Restricts users from printing and editing. Users cannot change these security settings unless they type the password you specify. You cannot use the same password that is used for Document Open Password. When you set a permissions password, only those people who type that password can change security settings. If the PDF document has both types of passwords, either password will open it. However, a user can only set or change the restricted features with the permissions password. If the PDF document has only the permission password or if a user opens the document by using the document open password, the password prompt appears when the user tries to change security settings.
Page Layout, Touch-up, Filling In Form Fields And Signing Existing Signature Fields:
Lets users insert, rotate, or delete pages and create bookmarks or thumbnail images, fill out forms, and add digital signatures. This option does not allow users to create form fields. This option is available only if a low encryption level (Acrobat 3.0) is selected.
Enable Copying Of Text, Images, And Other Content:
Lets users select and copy the contents of the PDF document. It also lets utilities that need access to the contents of a PDF file, such as Acrobat Catalog, access those contents. This option is available only if a high encryption level is selected.
Enable Text Access Of Screen Reader Devices For The Visually Impaired:
Lets users with vision impairment read the document by using screen readers. However, users cannot copy or extract the document contents. This option is available only if a high encryption level is selected.
You can delete a security setting if it is no longer required. However, preconfigured security settings cannot be deleted.