PDF Security Rec

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PDF Security Recommended Settings

Security settings for standard and DRM protected PDF files are typically set to prevent content copying and printing. Copying a standard PDF file between individuals cannot be prevented for standard PDFs, so for such files only the addition of a "Password to open" can provide some defence against accidental access to protected files. For protection against copying between individuals the only option is the use of a suitable DRM. Typically the settings for such files would be:

  • No copying of content (the default or only option from many DRM systems, including the offline solutions provided by Drumlin Security)
  • No printing of pages
  • No limit on the number of times a file may be viewed - but for some special documents, a low limit on the number of views, e.g. 3, and a hard or soft expiry date, may be desirable
  • A selected expiry date for the file (no expiry or a specific hard date, or an expiry date determined by the number of days the file may be viewed for)
  • For web-based PDF DRM there should be no downloading of the source PDF permitted (again, the default with the online solutions provided by Drumlin Security)
  • Static and dynamic watermarks should be included on every page of screen display (every viewable window should include a dynamic watermark). Note that the display window is not the same as the PDF page, where static watermarks can be added when the file is created or edited
  • Where printing is permitted, basic controls on its use should apply, notably adding static and dynamic watermarking, and limiting the output to physical print devices (i.e. not to PDF writers, Image writers, software-driven services etc.). Printed pages can always by photocopied and/or scanned into a multi-page image or PDF file, possibly with OCR, so the recommended additional protections for such files is important. However it should be noted that this is no different from any existing printed publication or pre-printed book, where copying and scanning cannot be prevented and where there is no real protection in the form of smart watermarking. Note that Javelin3 readers only permit printing to real, physical devices (as far as this is possible to determine), do not allow double-sided printing, and print pages as images. Printing should only be enabled if absolutely essential, and then it is recommended that users only print to their own printers, locally attached to their device (i.e. not at print shops or using in-network software-driven print services).