There are several ways to secure your PDF.
Protect > Password Protect
After clicking on the Password Protect feature, you will see this window popup.
Choose which feature you would like to use, then input and confirm the password.
If using Document Restriction, you will first get this message:
Click OK.
Then click
Then you will see this come up. The circled items below allow you to specify preferred restrictions.
Select OK.
Finally, an encryption algorithm of 256-bit is recommended.
If you frequently choose the same settings on this screen, you can avoid having to specify these choices each time by choosing above to "Set the settings as a new policy".
Going forward if you want to use this as a security policy template, simply select 
Choose the policy you want and hit "Apply to this Document". You can even edit the details if you want to change anything.
Action Wizard
If you want an easier way to secure documents over and over, use our Action Wizard.
Click on File > Action Wizard, then Create New Action. Select Create.
Then click on Protect > Secure Document > then double click on securing step you would like to move forward with.
In this case we double clicked on Certificate Protect. Once you do, action steps will appear on the right side. Click Add Instruction to describe what that step does.
Once complete, double click the next step.
Click Specify Settings. Modify according to your desired changes.
Press Ok. Add Instructions and continue to add until you desire for no more changes.
When complete, click Save and give it a name
Done!
