The Golden Ratio is a mathematical ratio, represented by the Greek letter phi, found in art, architecture, and nature, and is thought to represent a classic, innate, harmony of measurement. Most plastic surgeons know this, and also know that most faces do not have the classic golden ratio measurements.
Open the PDF and choose Tools > Protect > Encrypt > Encrypt with Password. If you receive a prompt, click Yes to change the security. Select Restrict Editing And Printing Of The Document. All Adobe products enforce the restrictions set by the permissions password.
You can easily password protect your PDF file so only the person who has the password will be able to see the PDF. The process is actually quite simple, however, the tools you need for this purpose come with a catch.