I work for a tech company, and yet I regularly need to manually sign digital files. What's the obvious way of doing that? Here it is:

  1. Print your file
  2. Sign your file
  3. Scan your file

That doesn't sound right. There must be some other way of doing this without wasting paper and ink, and without the pain of all those steps. Well, turns out there is one! It took me time to find, so I'm sharing it here, hopefully it will help others. The cool thing about this technique is that you probably already have the software that is required. Introducing... LibreOffice Writer! Yep, the Microsoft Word equivalent. You will need an extension though, called libreoffice-pdfimport. Install it simply with sudo apt-get install libreoffice-pdfimport and you should be good. Then the steps become:

  1. Make an image of your signature
  2. Open your PDF file with Writer, insert the image wherever you want, export as PDF
  3. Profit

Here are a few good points about this technique: first, your PDF file doesn't get turned into a flat image. Second, you can do a lot more than just adding an image. And third, it is much easier than using software like pdfedit.

For more details about how to use LibreOffice Writer and for the source of this post, please read Signing a document with an image in Ubuntu 12.10.