Use Encrypt PDF (formerly Protect PDF file) to limit access to a PDF document by setting passwords and restricting certain features, such as printing and editing (for additional reference, see How to password protect a PDF).
If you forget a password, you cannot recover it from the PDF. Maintain a backup copy of the original PDF that isn’t password-protected.
|Choose the original PDF that needs to be protected.
|Enter the name of the protected PDF.
|Enter a master password to secure the PDF and prevent changes to the security settings below.
|Choose between 128-bit (recommended) or 40-bit encryption.
- Not allowed prevents users from printing the document.
- High-quality (default) prints the document at maximum available resolution.
- Low-quality prints the document at no more than 150 dpi.
|Changing the document
- Not allowed (default) prevents users from making changes to the document, while Document assembly allows users to combine the PDF with another document.
- Allowed lets users insert, delete, and rotate pages, and create bookmarks and thumbnails using Acrobat Pro or another PDF editor.
- Not allowed (default) prevents users from copying any content, while For accessibility allows limited access for screen reader devices for the visually impaired.
- Allowed lets users copy text, images and other content from the document
- Not allowed prevents users from using any commenting tools, while Sign and fill in forms allows limited access.
- Allowed (default) lets users use the full range of commenting tools.