1. Open the PDF in Acrobat DC.
2. Choose
File >
Protect Using Password. Alternatively, you can choose
Tools >
Protect >
Protect Using Password.
3. Select if you want to set the password for Viewing or Editing the PDF.
4. Type and retype your password. Your password must be at least six characters long. The password strength is displayed next to your password to indicate whether the chosen password is weak, medium, strong, or best.
5. Click
Apply. Acrobat displays a confirmation message that the file was successfully protected using password.
