Acrobat 101: Simple Security
Remove sensitive information from a PDF file
If you want to store all your tax documents as PDF files on your computer (great idea!) but don’t love the idea of your social security number readily available to anyone who might be snooping around your files, this one’s for you. Redaction is the process of permanently deleting sensitive information from your PDF files; you’re not just scribbling on top of it or covering it up with a dark rectangle, you are Taking. It. Out. Forever. (Maybe this goes without saying, but don’t redact information from your files if you’ll need it later and don’t have it stored anywhere else, mkay?)
Here’s the quickest way to delete private information from a PDF document:
- With your PDF file open in Acrobat, open up the Tools pane and expand the Protection panel.
- You’ll see a section called “Black out and remove content”. This is where you’ll start the redaction process.
- The first step here is to prepare for removing the pertinent information. To do that, you’ve got to mark each item you’d like to remove. Marking content for removal lets you pick out all the things you want redacted from the document, but doesn’t actually permanently remove them (that part happens later). For now, there are two ways to go about marking up your document:
- You might have, say, four items that you want to redact. A photo and a name on page one, a phone number on page 2, and an address on page 3. No problem. Click on the “Mark for Redaction” tool and start drawing rectangles over everything you want taken out of the document forever. Acrobat highlights these items with a red box so you know what will be removed; if you hover over the box, it’ll turn black. Spooky.
- Drawing a rectangle gets the job done, but what if you’ve got a 2,000 page document and you need to remove a piece of information that occurs 253 times in those 2,000 pages? You could be drawing rectangles for hours, and still miss a few occurrences of that information. Not great. Instead, use the “Search and Remove Text” tool. This tool lets you run a search for a particular word or phrase, or a general pattern* (e.g. anything that looks like a social security number or a phone number) and automatically mark it for redaction. Once you’ve done the search, you can choose which instances of that word or pattern to mark for redaction. Much easier than the manual approach, right? Right.
- Okay, you just got through the hard part! You’ve chosen all the pieces of the document you need to redact. Now all that’s left is to apply those redactions. This step is the equivalent of cutting those pieces out of a paper document and mashing them into pulp: you’ll have holes in the document, and the information will not be recoverable. To make the redactions permanent, just click “Apply Redactions” in over in your Tools pane. Acrobat will ask you if you’re sure you want to continue; if you’re sure, take a deep breath and press OK.
- Congratulations, you’ve just added a bunch of black rectangles to your PDF file! But more than that, you’ve permanently removed potentially sensitive information from a document, rendering it safe for simple storage and protecting your data from menacing snoops.
*The Search and Remove Text tool only works on a document with searchable text. If you’ve scanned a document to PDF, you might have to take a few extra steps to make that document searchable. Here’s how to do that.