PDF Reader provides 2 ways for you to add password protection to PDF files:

Encrypt PDF (to the current PDF)

1. Open a PDF in PDF Reader

2. Click the “Security” icon on the upper toolbar

3. Choose “Set Password” from the pop-up menu, and then you will be brought to a window where you can select the encryption settings.

4. Select the output folder where you’d want to save the newly encrypted PDF file. You may also add more PDF files to encrypt by clicking on “Add Files”. 

5. Depending on how secure you want to encrypt the PDF, you can add a password to it to secure the content from being viewed, copied and printed

6. Then press the “Encrypt” button to start encryption

7. The new password-protected PDF will be saved in the output folder

Encrypt PDF (through Mac’s Finder)

1. Launch PDF Reader

2. Switch to the “Management” mode and click on the “Encrypt PDF” entrance under the office toolset section

3. You can choose the file(s), and then you will be brought to the encryption settings window

4. Choose an output folder and enter a password to encrypt the PDF(s)

5. The encrypted files will be saved in the output folder