Creating secure personalized watermarked PDF files
PDF Stamping: This is a term that is widely used to indicate that a PDF has had some form of “Rubber Stamp” applied to it, perhaps saying “Draft” or quite often something like “Confidential: For the Personal Use of XXXXX”. The latter is the case for some ecommerce sites where the details of the person ordering the PDF item is automatically “stamped” on their downloaded copy as a static watermark, to which Adobe-style security has then been applied. A typical example is provided by the digital distribution platform, SendOwl – for more details see:
Recent versions of Adobe Acrobat provide a range of “stamping” tools, as describe on the Adobe website. Older versions of Acrobat do not include a separate stamping function but can use the watermarking facility instead.
Of course this mechanism provides no real protection of the document, since the security and thus the watermark can be removed easily, and there is nothing to prevent the file from being forwarded and shared anyway. For greater protection a different form of personalization is required, combined with digital rights management (DRM).
The Personalization tab in the DrumlinPublisher software is a special facility that can create multiple secure copies of a single input PDF file, each uniquely watermarked and named. The personalization procedure is quick, flexible and can generate from one to many secure (encrypted and DRM protected) personalized files from a single input PDF. It does this using information in a simple text file, as described below.
Select list: This is a list containing up to three, comma separated text entries per line – the first entry (Field 1) on each line is the target user’s name, and in the example shown below the user’s email address and company name are provided as Fields 2 and 3:
James Cameron,email@example.com,ABC Ltd
Bob Hope,firstname.lastname@example.org,DEF Ltd
DrumlinPublisher uses these fields to create personalized secure versions of the source PDF file. For example, if the source PDF was the file ftse.pdf, the first two output secured files would be ftse_James Cameron.drmz and ftse_Bob Hope.drmz.
Unique authorization codes for each user can also be generated automatically at the same time. Each generated secure PDF file will include a watermark identifying the individual based on the details in this list, for example: “(c) 2018 Licensed to: James Cameron, ABC Ltd – email@example.com“.
Personalized Watermarks: The way the watermarking works is by replacing special “placeholder” fields (%1, %2, %3) with the text from the Fields 1, 2 and 3 in the list of names, so the result is essentially an automatic edit operation creating a static watermark element on every page, just as if the name had been manually edited onto the document using Adobe Acrobat. But unlike a standard PDF the personalized watermark on the secured files cannot be removed by the recipient – it is part of the securely encrypted output document. Furthermore, because each file is uniquely named, activity log data that is available via the DRM server will identify the activities relating to the named document at each step of the process.