Protecting PDF files The Right Way

One of the main attractions to publishing a document as a PDF file is the fact that this file is a read-only format. Since any edits to this type of document leaves a digital footprint, these files meet the legal requirements of a court of law. Not only can you track changes, you can also choose to restrict the ability for others to edit the content, even if they have PDF software of their own.

What’s more, PDF protection measures beyond a simple password-protected file that’s easily cracked using a brute force tool found on the Internet. You can completely lock the file. You have the option to protect content from being printed or copied. And you can allow everything but changes to certain sections of the file itself. Let’s take a look at the basics.

Using password protection

When it comes to security, it might seem like the password is at the foundation, however, what really protects a document, like a PDF, is encryption. When creating a file using PDF software, you have the ability to password protect the document. Simply follow the steps to create a “document open” password and your PDF software does the rest.

Behind the scenes, the encryption algorithm scrambles the file contents. Now only a person with the encryption key, or password, is able to open the file for viewing. For confidential and sensitive information, this adds an extra layer of security for information stored on a file server, sent via email or shared using other methods of file transfer. This process can help protect your publishing rights.

If your PDF software uses a strong encryption algorithm, such a 128- or 256-bit AES or 128-bit ARC FOUR combined with a good password, common password cracking tools will have an extremely hard time trying to open your file.

Protecting elements of the document

If your goal is to allow the general public to view your document but you want to prevent them from performing certain actions, most PDF software applications will allow you to create this type of security as well.

You have the option to protect a PDF document from:

  • Readers editing or modifying content
  • Printing
  • Having the content copied
  • Copying done by taking a screen shot
  • Adding digital signatures to the file
  • Having content extracted from the file

You can also set a password to allow these actions for authorized users.

A good password

Your PDF software’s ability to encrypt the file is enough to protect the document, however, there’s still a weak link in the process—and that’s the password you create.

Simple passwords are easily guessed by a number of tools available on the Internet. Some experts stand by the strong password theory of using upper and lower case letters combined with numbers and symbols. The downside is, these types of passwords are hard to remember when you’ve got a string of characters like A6**jdhEW87. That’s why many people tend to turn regular words into strong passwords, like [email protected] Unfortunately, password-cracking tools now take these types of passwords into account, so they’re no longer a sure thing.

To adequately protect PDF documents that use a password, or anything else that requires a password for that matter, use a phrase instead. This makes it harder for brute force tools to guess and it’s easier to remember. Also, make sure that the password is unique; not something you’re using in another account, especially for passwords shared with anyone who has access to the document.

Many PDF software tools, like Foxit PhantomPDF, will prevent the wrong people from viewing a document but still allow search engines to see the metadata for proper indexing in the results page and ensuring your document gets found.

Even though passwords created by PDF software have the ability to completely lock down a document, professional grade applications will allow you complete control over what you hide from the public. It’s this type of complete control that makes PDF files the most practical way to secure your content.

21 thoughts on “Protecting PDF files The Right Way

  1. Lobo

    Hi, I’m using foxit and have tried the password protect option. However someone with another pdf application can still go in and make changes to my document without putting in a password. Am i doing something incorrectly? These are the steps followed:
    File – Properties – Security – Password Protections
    Changes allowed none, check box for extracting pages allowed is checked, Printing: high resolution

    What am I missing?

  2. Martin Boyle

    I’m creating Ebooks with Foxit Phantom to sell on my site, how can I protect them from, copy and paste by my customers. After protection is applied, will my customers be able to download their product and open it as normal?

  3. AlainCh2

    Same problem here, BUT I know the password.

    So I can open them .. but how to save them REMOVING THE PASSWORD?

    Cannot find anything into the ribbon nor in “protect”

    Many Thanks

    1. FOXITBLOG Post author

      To remove a Password you need the Foxit PhantomPDF product.Go to Protect – Remove Security.Then enter the password.
      Please note you must know the password to remove security.

  4. AlainCh2

    same problem her BUT .. I konw the password.

    How to save .. removing the protection??

    Cannot find it into the ribbon under PROTECT

    1. FOXITBLOG Post author

      To remove a Password you need the Foxit PhantomPDF product.Go to Protect – Remove Security.Then enter the password.
      Please note you must know the password to remove security.

  5. sagar

    I have a PDF file which i want to protect by giving password. Is there any system has in foxit so that people can see this PDF but can’t convert it to word without that password?

    1. FOXITBLOG Post author

      You can use Foxit PhantomPDF to Password protect a PDF . To password protect a PDF document using PhantomPDF Standard, please open the PDF (that you want to secure) > Select Protect > Password Protect > Check the option Require a password to open the document > input password and confirm > Select OK. Once save,d the PDF document will require the password in order to open the document.

      If you wish to prevent the user from editing/printing/copying the PDF, this would be the same workflow however the option you will be selecting is “Add Document Restriction” > Select Permission and deselect the options you do not want > select OK > Select OK again. Once saved, this will require a password in order to perform the functions you deselected.

  6. James Toombs

    I did not intentionally password protect my documents and only discovered they were protected when I attempted to open them today. I’m not the panicking type but I’m getting very uncomfortable. How can I get into my docs?

    1. FOXITBLOG Post author

      If you put a password on a PDF and do not know that password, Foxit would not be able to discover this password and unlock the PDF. It is important that when you password protect a document that you remember this password or record this password in case you forget it. Foxit does not automatically password protect PDFs in any manner. For any further questions or concerns,please contact [email protected]

      1. Josh

        I have a similar problem.

        I fill out PDFs, sometimes sign them, sometimes not, save them, and when I or someone else opens them again using Adobe Acrobat Reader DC, they are locked. Neither I nor other parties can input any further data into the form.

        I did not choose any type of password or password protection. It seems to me that Foxit DOES apply password protection as a default.

        I also have virtually no access to any of the security or protect options.

        Please explain what is going on here. This is an extremely frustrating situation as I am unable to find any way to unlock these documents and like I said, I never chose any type of password so I have no idea what the password would be. Not that knowing it would help, because I can’t even access/find a screen that offers me the opportunity to even enter a password.


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