NSA issues redacting guidelines

The report explains how officials can effectively remove classified information from public documents.

Concealing classified information in digital government documents is not as easy as striking out text with a black marker. Today’s digital documents make the task more complex, but the National Security Agency has now given agencies specific instructions.

NSA’s report, “Redacting with Confidence: How to Safely Publish Sanitized Reports Converted from Word or PDF,” states that merely covering is not enough. “The way to avoid exposure is to ensure that sensitive information is not just visually hidden or made illegible, but is actually removed from the original document,” according to the report, dated Dec. 13, 2005.

Editors make three common mistakes when redacting Word documents before they are converted to PDFs, according to the report. They merely cover the classified information with black highlights and rectangles and make the images “ ‘unreadable’ by reducing their size.” Editors also forget about the hidden information most office documents, such as Word, contain, the report states.

To solve the problem, NSA recommends making a copy of a sensitive document and editing the copied version. Then, copy and paste the text to a new blank document. Finally, editors should save the clean document in PDF form.

“While time-consuming, these steps give the highest confidence that sensitive information is not hidden in a released document,” the report states.