Canon MG8100 series On-Screen Manual page 618

The Password Security -Settings dialog box opens.
Setting Passwords for Existing Files
In the View & Use window, select image/PDF files and click PDF.
1.
Click Create/Edit PDF file on the list.
2.
Creating/Editing PDF Files
Edit files in the Create/Edit PDF file window, then click Save Selected Pages or
3.
Save All Pages.
The Save as PDF file dialog box opens.
Select the Password security settings checkbox.
4.
The Password Security -Settings dialog box opens.
Note
You can also open the Password Security -Settings dialog box by clicking Set..., then selecting
Password Security for Security in the PDF Settings dialog box.
2.
Select the Require a password to open the document or Use a password to restrict
printing and editing of the document and its security settings checkbox, then enter a
password.