Ask A Cartographer

Securing PDF maps

November 06 2009 | 2 comments
Categories: Publishing

We use PDF maps to market our subscription data, but how can we secure these maps against reverse engineering, dissassembly or georegistering in order to protect our data against piracy?

Is it possible to create cartographic output in a secure manner without compromising too much on quality? Would obscuring the projection and datum (or choosing odd numbers for standard parallels and origins) still allow an aestetically pleasing reference map to be useful, yet difficult to georegister?

Technically it is possible to secure PDF documents against copying and editing, but a Google search for "PDF security" returns results that offer to remove such restrictions for $10!

What are the cartographic precautions that can be taken so that the map effectively serves a marketing purpose for proprietary data?


Mapping Center Answer:

That's an interesting question I've not heard in quite a while.  So, first the answer, which is you will need Acrobat Professional from Adobe. Open your PDF output from ArcGIS and then set up security in Acrobat Professional and save the file.  This can be automated--one of our larger customers has done this for a number of years.

My recommendation is not to compromise your cartography for the sake of perceived security.

No file security is perfect; but by taking precautions, like those available for PDFs in Acrobat Professional, you reduce the number of qualified hackers to near zero.  Couple that with the idea that your data likely are not worth an extreme effort to steal.  Yes--we are all annoyed when we find somebody has used our data or maps without permission, but a simple cease and desist letter usually takes care of the problem. The odds of a serious commercial threat stealing your data are probably minimal.

Last, I cannot imagine Google or Adobe authorizing or supporting an application that strips an author's security measures on download.  If anything, the industry has moved in the other direction, allowing more and more security options.

For instance, you could choose to use a font that takes advantage of some of the OpenType security features that are supported in PDF.


Digital Watermarking posted by Fred Woods on Mar 17 2010 9:33AM
Put the security in the image. Use GCS Research's GeoMarc technology for ArcGIS. Read more about GeoMarc at
Thanks! posted by Aileen Buckley on Mar 17 2010 9:53AM
Thanks for the tip!

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