Three ways to secure PDFs

In the wake of the Equifax scandal and the Cambridge Analytica fiasco, more people around the world—in business, government, and their personal lives—are paying attention to the importance of cybersecurity.

And yet, despite the billions of dollars on the line and the valuable personal information at stake, most people remain woefully unaware of basic steps they can take to protect their data and enhance their overall security, whether online or offline.

One easy place to start is with a file format nearly everyone is familiar with—the PDF (or Portable Document Format).

In the late 1990s, PDFs became the most popular file format for maintaining and sharing documents on computers and the internet. PDFs are used by governments, universities, large and small businesses and corporations, and individuals for every kind of document imaginable.

Securing your PDF files is simple, takes almost no time, and could save you or your business from a lot of grief down the road.

Put a password on it

Beyonce once said, “if you liked it, then you should have put a password on it”—or something like that. Who knew that one of the world’s most celebrated pop stars is also a cybersecurity expert?

Securing your PDF document with a password is easy, but it’s important to remember that there are two security levels you can choose from when password-protecting your document.

The first applies a password to the whole document, rendering it inaccessible to anyone who doesn’t have the password. If you’re sharing your document with a collaborator or customer and you choose this option, you’ll need to provide them with the password before they can open the document.

The second level places restrictions on what can be done in the document. You can turn printing on or off, for example, or prohibit readers from copying text or manipulating the document. You can place all sorts of restrictions on your document, according to your particular security needs.


The government is notorious for redacting its national security documents. Are officials sometimes overzealous? Maybe. But when it comes to security, they’re probably onto something.

When you redact a document, you place a black line over the sections of text you want to keep away from prying eyes. Adobe allows you to easily redact as much or as little of your document as you want.

There are two options to keep in mind when you wish to enhance the security of your document by redacting sensitive information. The first option simply colors over the sensitive text. If you’re the owner of the document, you can remove the lines whenever you want, restoring the document to its original state.

The downside to this approach is that a sophisticated user could also figure out a way to remove the line, revealing the sensitive text underneath.

The second—and more secure—option actually removes the text and replaces it with the redaction lines. Not even the savviest hacker could make text appear that doesn’t exist.

Certified safe!

One last step you can take to secure your PDF documents is to “sign” them with a certificate-based signature. I put “sign” in air quotes because, although digitally signed PDFs can contain a genuine John Hancock, the real action takes place below the surface, at the level of encryption.

Like a regular signature, a certificate-based signature identifies you, the person signing the document. However, your digital certificate is much more difficult to forge than your real one, because it is comprised of encrypted information unique to you. Multiple people, each with their own digital signature, can digitally sign a document.

When a document is digitally signed, any subsequent changes render the signature invalid. This makes it easy to identify if your PDF has been tampered with. Some PDF tools even allow you to attach a digital timestamp to your document. If someone alters your PDF, you can see when the change happened.

Security is not difficult

The news is replete with unnerving stories about increasingly sophisticated cybersecurity threats. These stories, however, often scare readers away from taking basic precautions to protect themselves and their data out of a misplaced fear that only cybersecurity experts can keep them safe.

The reality is that most security breaches and hacks happen because people fail to take basic preventative measures to keep their information secure. Simple steps, like protecting your PDF documents, can save you time, money, and the embarrassment of losing sensitive information.