Managing Digital Content - by Zach Cox - 12 Dec 2010


I am currently struggling to get some eReader on an iPad that will work with the Public Library's downloadable lending library.


This really is a 'bleeding-edge' sort of thing where you have to install a version of the reader software that knows how to 'expire' an eBook so after a week, or two weeks or whatever your eBook that you downloaded from the public library 'goes-away'.


Adobe Digital editions do have such a reader but sadly, for the public library, there is no single system that works on most 'small-digital-reader' systems.


This is because; the device (as opposed to the content that is consumed on the device) is NOT considered the main thing.  Another way to say this is that you purchase one record player and many records so the record player becomes the cheap part and the content is where the financial return comes from, and there is little interest in really making some fundamental changes in the ‘players’ so that they can manage the content.


So, the concept of a 'lending-library' works very nicely when there is NO distinction between the player and the content (i.e. an actual book). But as they become more and more separate the idea of how to 'lend' content without 'giving-it-away' becomes more difficult.


The solution is to invent digital content that 'expires' and can be ‘lent’.  The concept has a 'lagging' technological piece that is necessary to implement it, which is the idea of an 'on-line-player'.


By this I do not mean that the content needs to be continuously online but instead the player can collect the content once but then verify by going 'online', intermittently to see if the content is still valid.


Once we have the technology in hand to securely sign and then attribute that signature we could 'lend' content, just as we do with actual books.  The difference would be that if you lent me some digital content that you owned you could say for example, "Zach, here is my copy of The Light of Other Days, I'll lend it to you."


At that point the key phrase is 'LEND' (rather than) 'GIVE'.  And the book could be returned either by me or by you at any time just by changing the current owner of its certificate back to 'John' and away from 'Zach'.  If you had said, "Zach ... I'll give it to you.", then you would have changed its signature so that you could not 'take-it-back'. 



So here are some ways digital content can be made to behave.




-   CONTENT - This is the digital content; a picture, a document, an audio file, a video file, any collection of binary digits.


-   PLAYER - This is the device that the content is consumed on.


-   TRUSTED CERTIFICATE SERVER – This server together with the Trusted Programming Module of the player is responsible for managing the certificate associated with each content object.  These servers are currently in use around the world but do not (currently) manage certificates like the ones described here.




-   CERTIFICATE - This is an integral part of the content and is woven in to the binary file like a 'watermark'. When all the binary digits of the content are run through an algorithm the content and the certificate together make up the digital signature of the content.  Another way to think of digital content is that it and its certificate are one in the same.  Or to say it another way: There is no such thing as ‘removing-the-certificate’.




-   TRUSTED PROGRAMMING/IDENTIFICATION MODULE – This is built into the player and is responsible for managing the CONTENT on the PLAYER and making sure the person operating the player is the correct CONSUMER.  This module when online to a trusted certificate server can manage the CERTIFICATES associated with the CONTENT on the player and request transitions of the CERTIFICATES associated with the CONTENT on the PLAYER to new values.




-   OWNER – This actor sets who the CONSUMER is. There can only be one OWNER.  The OWNER can set the CONSUMER to a different person than himself by doing a “TO LEND” transition. The OWNER can also set a new owner by doing a “TO GIVE” transition.


-   CONSUMER – This actor can consume the content.  There can only ever be one CONSUMER at a time.  And of course, when the OWNER is consuming the content he appoints himself as the CONSUMER.


-   CREATOR – This actor approves the “TO PURCHASE” transition. The CREATOR cannot be changed.






-   TO GIVE – This action is taken the OWNER and sets a new OWNER value, (and the CONSUMER value is cleared).


-   TO LEND - This action is only taken by the OWNER and sets the CONSUMER to a different person than himself. The CONTENT transitions to the “ON LOAN” state


-   TO RETURN – This action can be taken by the CONSUMER and sets the CONSUMER back to the OWNER.  The OWNER may also take this action to get the content back from a CONSUMER.  The content transitions back to the “IS OWNED” state.


-   TO DUPLICATE – This action is taken by anyone and when it occurs the OWNER and CONSUMER are cleared and the state is set to the “INITIAL” state.


-   TO PURCHASE – This action is taken by anyone when the content is in the “INITIAL” state and is used to set the OWNER value.  This action is always approved by the CREATOR.  The content transitions to the “IS OWNED” state.



-   ON LOAN – This state occurs when the OWNER and the CONSUMER are different people.


-   IS OWNED – This state is set when the OWNER and the CONSUMER is the same person.


-   INITIAL – This state is set just after a “TO DUPLICATE” transition occurs and the OWNER and the CONSUMER are cleared.  The content can only be consumed when it is in the “ON LOAN” or “IS OWNED” state.