When I first heard on the radio that secret information had been found hidden in a document given to media by the U.S. military in Iraq, my first thought was Microsoft Word.
Most people dont realize how much information Word (along with PowerPoint and Excel) stores with your document, including previous versions and some changes. But the culprit was Adobe Acrobat, not Microsoft Word. Reporters found they could remove the black from blacked-out areas of the PDF document and read the text underneath.
Apparently, someone in the military thought he could redact the document just by blacking out the text he wanted to keep secret. But if you open the document in Adobe Acrobat, the original text is easily uncovered, as the Army found out—presumably to its horror since the information included "rules of engagement" never publicly released and useful to enemies planning attacks.
The mistake was understandable. The security in Adobe Acrobat is somewhat confusing, even misleading. You can keep people from opening a document, or copying, or printing. You might therefore think you could keep people from changing the document as well. But youd be wrong.
And I would have been too if youd asked me before I researched this a few months ago. I was building a form and wanted to make it easily available but still prevent changes from being made to it. For a program that is promoted as a publishing tool, youd think its output files could be locked against changes.
I can easily imagine someone making such a mistake and believing it possible to lock the layers of the Acrobat document so the layer with the blackouts couldnt be lifted away from the layer with the text.
"We dont market or sell Acrobat as a redaction tool," an Adobe spokesperson told me when I called to inquire.
He referred me to a company called Appligent, which offers an Acrobat plug-in specifically for redaction of information in government and court documents.