How to Encrypt a PDF to Share Sensitive Data Safely

Anyone who takes the time to create a PDF file usually wants the contents to be protected to some extent. If you didn’t care about anyone tampering with the document, you would simply share the Word document or Excel spreadsheet. Unfortunately, today changing the contents of a PDF is something anyone can do using Microsoft Word or a similar program.

If you have Word or Adobe Acrobat, you can protect your PDF files by encrypting them and adding a password. Before doing that, however, it’s important to note that the protection you give these files is very limited.

The Limitations of Secured PDFs

Document-level security is a good way to protect files from being opened and tampered with by casual users, but that’s the extent of it. Without additional precautions in place, encrypting and putting a password on a PDF document isn’t going to cause many problems for a serious hacker. In fact, anyone who is motivated to can simply turn to Google and find the free software to access your protected file.

Password-protecting a document is much the same as those little locks you see on a briefcase. Anyone with a nail file or heavy object can get inside if they actually want to — and when they do, you’ll never know it. Unlike with server-level security, you won’t get an email or a text message letting you know your file has been compromised.

That being said, it’s still good security when you’re sharing a file with someone who isn’t motivated to hack it. A supplier or a new hire, for example, isn’t likely going to risk altering the words on a write-protected contract before signing it and returning it to you.

How to Encrypt a PDF With Microsoft Word

Microsoft Word gives you an option to encrypt and password-protect documents when you save them, including PDF documents you create in Word. To use this feature:

Open a document in Word, and when you’re ready to create a PDF, click the File menu and select “Export.”
Click the “Create PDF/XPS” button to export the document as a PDF file.
Click the “Options” button when the Save window opens, then select “Encrypt the document with a password” and click “OK.”
Type a strong password in the text field and click “OK.”

Protecting DOCX Files With Word

You don’t have to create a PDF to password-protect files in Word. If you’re creating a DOCX file, you can put a password on it too.

Open the document with Word.
Select “Info” from the File menu and then click the “Protect Document” button.
Click “Encrypt with Password.”
Enter your password, click “OK” and then confirm your password.

Anyone opening the document will be prompted to enter the password first.

If you ever forget your password, don’t worry too much about it. Microsoft has a free DocRecrypt tool that anyone with administrative access can use to strip the password from a protected document, or reset the password, with just a few keystrokes. This is a valuable feature if someone password-protects their documents and leaves your company.

Security Features With Adobe Acrobat

If you create a lot of PDF documents, Adobe Acrobat is your best option for protecting them. Not only can you encrypt and password-protect the documents, you can prevent people from editing, copying or printing them.

When you set the encryption on an Adobe PDF, you should always choose the most recent versions, since they use better encryption than the older versions:

Acrobat X (PDF 1.7) and later: uses 256-bit AES encryption.
Acrobat 7.0 (PDF 1.6) and later: uses the AES encryption algorithm with a 128-bit key size.
Acrobat 6.0 (PDF 1.5) and later: uses 128-bit RC4 encryption.

The only problem with choosing a recent version for access is that if someone (like a client) doesn’t have the most advanced version of Acrobat, they won’t be able to open the file. However, they can always download the latest version of Adobe Reader to access the PDF. Adobe Reader is free and easy to install.

How to Encrypt a PDF Using Adobe Acrobat

Encrypting a PDF file with Adobe Acrobat takes just a few clicks. Once you open the PDF with Acrobat:

Click Tools > Protect > Encrypt > Encrypt with Password.
Click “Yes” if you’re prompted to confirm that you’re changing the document’s security.
Select “Require a Password to Open the Document,” and then enter the password.
Select which versions of Adobe Acrobat your PDF will be compatible with.
Click “Encrypt All Document Contents.”
Click OK, then confirm your password when prompted and then click OK again.

If you just want to protect the PDF from being edited but you want anyone to be able to open it without a password, then you can select the “Editing” option instead of requiring them to use a password to open the document. After selecting “Editing,” you have the choice to restrict editing only or to restrict PDFs from copying, printing or editing. Whichever you choose, anyone wanting to perform these restricted functions will require the password.

Securing PDF Files With a Document Management System

If your PDF files contain sensitive information, simply encrypting them with a password isn’t going to be enough to protect the contents. All anyone usually needs to do is to drag the PDF onto a website to gain access to its contents — just search “crack PDF password online” to see how easy it is.

Caplinked clients have 24/7 access to their own secure document management system, which encrypts and protects all of their documents. They can restrict access, editing, copying and printing at the server level, not the document level. And they can even control access to files after they’ve been downloaded, using FileProtect DRM.

To take a look at the options and the easy-to-use interface, get started today with a free trial.

David Weedmark is a published author and e-commerce consultant. He is an experienced JavaScript developer and a former network security consultant.