Last week I released the code for a PDF watermarking action for Alfresco.  While watermarking is certainly useful, I have much more extensive needs around PDF documents.  I need digital signatures, document permissions and encryption.  Well, as of today, the last two are up and running!  Using the same iText library that powers the PDF watermarking actions, I have just completed a PDF encryption action.  To try it out, either download the updated AMP (version 0.92, available here) or build it from the project source, install the module, and restart your Alfresco server.  When you view the list of actions, you will see a new item in the list, Encrypt PDF.

The encryption action can take a few parameters.  Only one, the destination space, is required.  The rest are optional.  Notice that there are two password fields.  The first, the user password, is used to set a password that is required for user access to the document.  The second, the owner password, is the password that will be required if you attempt to modify the document permissions after it has been encrypted.  The following document permissions are also supported:

Allow printing
Allow copying
Allow modification of contents and annotations
Allow form fill
Allow screen reader access
Allow degraded printing
Allow document assembly

The last checkbox is used to set whether or not you want metadata included in the encryption operation.  If you choose to encrypt the metadata, the document will most likely not show up in any search results, as Lucene will not be able to index it.  Leaving the metadata unencrypted at least allows this portion of the document to be indexed.  Finally, there is a choice of encryption levels.  Standard PDF 40 / 128 bit encryption are supported, along with the more secure 128 bit AES.

I have tested this with a variety of PDF documents, and so far everything is working as intended.  If you run into any issues with this action or the PDF watermarking, please open an issue at the Google Code project.

Enjoy!