When “Confidential” isn’t Good Enough: Preventing Unauthorized Distribution with PDF Watermarking
One of the tools that has emerged in the effort to keep confidential content from being distributed beyond its intended audience is PDF watermarking (sometimes referred to as PDF Stamping). PDF watermarking consists of placing text and/or images, often semitransparent, somewhere on the pages of a PDF document. The watermark may consist of a company logo, or a reminder to the recipient that the material is “Copyright”, “Not to be Redistributed” or “Confidential”. Although watermarks of this nature serve as a reminder to recipients, PDF watermarking of this kind does little to dissuade those whose respect for privacy and intellectual property leaves something to be desired.
To realize the full potential of PDF watermarking it is important that the watermark include the name, or some other identifying feature, of the recipient. For example, if John Smith, working on a film in development, is emailed a copy of the script, do you think Mr. Smith would be more likely to email it along to his friends or movie website if the watermark running across the pages of the PDF said “Confidential”, or if watermark read “This Script is Only to be Read by John Smith”. Although “Confidential” clearly spells out the intention of the distributor, John Smith can still be confident that if he does pass along the script, it is highly unlikely that he would ever be found to be the source of the script’s release. However, by individualizing the PDF watermark by name, John Smith is now accountable for keeping the script confidential. If John Smith were to pass it on, he would run the very real risk of having the script appear on the internet and having the leak traced back to him through the watermark it contains.
Although a movie script is used as an example, PDF watermarking would be just as effective for deterring unauthorized distribution for architectural designs, eBooks, and any other intellectual property or confidential material in PDF.
PDF Watermarking: think of it as the honor system with added incentive.
