Acrobat for Legal Professionals

December 16, 2005

Redacting PDFs

Redaction, by definition, means removing information from documents. In the old days of paper, xacto knives were used to cut text from the paper and it was then photocopied with a black sheet of paper behind it.

As numerous folks have found out, covering up information in an electronic file is not the same as deleting it.

Note: This article was written before Acrobat 8 shipped which includes robust tools for detecting improper redactions (Acrobat 8 Standard and Pro) and full-featured Redaction tools (Acrobat 8 Professional).<\p>

There have been numerous cases recently where improper redaction led to accidental disclosures:

  • A PDF distributed by the US government contained covered over text that was fully accessible. In this case, the user authored a document in Microsoft Word and used Word's Tables and Borders toolbar to set the background color to black. Thus, black text on a black background which was not visually readable, but does not eliminate the data. When the user converted the document to PDF, a simple search of the document revealed the text. Note here that Acrobat worked as advertised properly preserving every element of the document.
  • Another case of an improperly redacted PDF was related to me by a large law firm's trainer. She had added black filled rectangle annotations using Acrobat to a document and secured it using a password to prevent changes. She quickly learned that you can simply turn off printing of Annotations in Acrobat's print window!

Acrobat annotations are not meant for redaction. They are used for notes, comments and callouts.

The best way to redact a PDF is to use PDF Redaction software.

Appligent http://www.appligent.com offers Redax for Acrobat. There are two versions- Redax and Redax Lite. These operate as plug-ins within Acrobat and allow you to completely and securely delete text and graphics from the document.

It has a variety of other features such as search and redact, etc. We like it so much at Adobe, we sell it in the Adobe on-line store!

There is another alternative which doesn't require any special software, but I do not recommend it unless you are . . .

  • Really, really careful
  • Seldom need to redact

  1. Go to Tools-->Drawing Markups-->Rectangle
  2. Draw a rectangle to cover the offending text/graphic
  3. Right Click on the rectangle and set the Fill to Black. Click OK.
  4. Select the rectangle and choose "Set Properties to default" so that each additional rectangle will be solid black
  5. Alternately, you can use the Highlight tool to highlight text (if you have a PDF Normal or Searchable PDF). Set the highlight color to Black.

rectangle_properties.gif

At this point, all you have done is to cover up the items you want to redact.

To *really* get rid of the information, you need to flatten the file.

  1. Go to File-->Save As
  2. Choose TIFF from the Type pop-up at the bottom of the dialog box

Acrobat will save each page of your PDF as a separate, sequentially numbered TIFF file.

You can now recombine the TIFFs into a single, image-only PDF.

  1. In Acrobat 7 Standard or Pro, click the Create PDF button on the toolbar
  2. Choose "From multiple files"
  3. Click the browse button and navigate to the location you saved the files

create_multiple.gif

If you have a lot of these to do, you can Save to TIFF and create PDF from TIFF in batch using Acrobat Professional.

Redaction Futures

I frequently hear from my law firm and corporate legal customers that they would like Acrobat to include native redactions tools. To me, there is no doubt that the customer demand is there. I hope that someday Adobe will include best-of-breed redaction tools in our products.

Until then, I'm interested in hearing your opinion which I will share with our product team. Let me know in detail how you could envision redaction tools working in Acrobat. I look forward to hearing from you.

Posted by Rick Borstein at 12:39 AM on December 16, 2005

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