To display this dialog box, select Security > Security > Manage Security > Modify, then select Password Security in the Security Method list.

The Password Security dialog box offers the following controls:

• Compatibility: Specify compatibility level (40-bit, 128-bit for different PDF versions, 128-bit or 256-bit AES - Advanced Encryption Standard).

• Select Document Components to Encrypt: Select from the options: Encrypt all document contents, All contents except metadata, or File attachments only (options depend on the encryption level).

• Allow Document Opening Only by Password: Set this as a prerequisite for opening the current PDF document in future. If it is set, then you need to specify the password in the Document Open Password edit box.

• Set a permissions password to restrict editing of security settings: Set this and select permitted actions from the drop-down lists for printing and changing the document, enable or disable copying different contents, enable or disable accessibility for screen readers to read aloud textual contents for visually impaired. This password will be needed to modify these settings or to change passwords in future.

As you click OK, you need to confirm the Open and/or Permissions Password in the Password dialog box.