Redacting a PDF seems like it would be the easiest thing in the world. Just draw one of those black boxes over the text you need to have disappeared, and voila! Redacted! Except that your recipient can actually just place their cursor over that part of the document, copy, and paste it into a new document.
This is exactly what happened a few years ago in a patent infringement lawsuit involving Apple and Samsung. The judge’s decision contained redactions, but a simple copy and paste revealed everything beneath. If you want to make sure you’ve actually redacted something before sharing it, there are several methods—all of which are more secure than the black box.
Redacting Using Adobe Acrobat Pro DC
You probably already have Adobe’s Acrobat Reader, because everyone does, but you can’t perform redactions with it. You gotta have the Pro version to redact. Redacting in Adobe Acrobat Pro is very simple. The main problem with this method is you need Adobe Acrobat Pro. It is not cheap.
You can buy a subscription the desktop software, Mac or Windows starting at $14.99 a month if you agree to a year-long commitment. Acrobat Pro is $24.99 if you want to go month-to-month. It offers a lot of features to edit, review, and create PDFs, so it’s worth the purchase if you’re a frequent user of PDFs.
If redaction is a real rarity (as in a one-time thing), you can download a free 30-day trial of Adobe Acrobat Pro.
Adobe provides an overview of how to redact documents and remove sensitive information. It really only takes a few clicks.
First, open the document you wish to redact, go to the Tools menu, then select Redact.
Doing so will bring up the redaction tools when you hop back to your document. Select Mark for Redaction and Adobe will pop up a handy reminder that redacting is a two-step process.1
From there, just highlight the text you want to redact. Acrobat will outline it for you in bright red.
Click Apply to redact… but first, Acrobat will ask if you are really sure you want the material gone.
Click OK and your text will disappear forever. Acrobat will then ask you if you want to find and remove any other hidden information.
You should always say yes to this. Acrobat is asking if you want to remove the metadata, and you always want to remove the metadata. In this document, there’s nothing particularly secret, but the metadata does let you know I’m on a Mac and that I made this PDF with Microsoft Word originally.
Scrubbing the metadata ensures that any author information, revision information, or anything similar gets completely excised from the document. There is no reason to ever hand over a PDF before you’ve scrubbed the metadata.
Paid Alternatives To Adobe Acrobat Pro
The cost for Acrobat Pro DC can add up over time. Unfortunately, super-cheap or free PDF redacting is hard to come by. Most of the free PDF redactors online require you to upload your document to the website before you can redact, which raises all sorts of ethical and security concerns.
There are a few alternatives, though. If you are on a Windows machine, consider NitroPDF, which will run you $159/user. You can get a free two-week trial to check it out. Foxit makes Foxit Redactor, which is software solely to redact Microsoft Word documents. It’s an Office plug-in, so you access the redaction tools within Office itself, which is handy. It costs you $39.95 and also comes with a free trial so you can see if you like it. However, Redactor only works on Windows and only works within Office, so it is limited to documents you create (or already have in an Office format), not PDFs you’ve received.
Another option for Windows users is PDF-XChange Editor, which will set you back $54.50. It offers a number of features, including a redactions. It does offer a free version with reduced features if you want to give it a try.
For Mac (Windows, and Linux) users, LibreOffice is an office suite that allows you to edit PDFs. It’s free to use, however, it doesn’t have a function that redacts texts. Instead, you’ll have to “Find & Replace” what you want to redact with block symbols, which is a cumbersome process if you have a large document or many things to redact.
Make Sure Your Document is Redacted
For the more thorough or paranoid among you, after you’ve redacted a PDF, use another PDF editor to make sure someone else can’t just open up your document and unredact it. You should also open your document in a text editor and search for what you redacted to make sure it doesn’t show up that way either.
Sometimes low-tech (or no tech at all) is the easiest-and cheapest-approach. Print out your PDF, black marker the heck out of it, scan it, and send it. Just remember you really do need to make a few passes with that black marker to completely obliterate things.
If you don’t feel like printing, marking, and scanning, you can do something similar via computer. Take your PDF and draw a black box in Acrobat Reader or Mac’s Preview or any similar PDF reader. After you do that, take a screenshot of your document. The resulting image is just that—an image—and therefore can’t be manipulated in Word or any other program. The problem with these two methods is that you are left with a document that isn’t searchable or conducive to redlining or commenting.
Bottom line: If you are in the type of practice that requires a good deal of document redacting, it is probably best to invest in a dedicated program that ensures the data you’ve redacted is actually gone. The price will be worth the peace of mind.