November 1, 2007 - the reflector has held a number of discussions on the Forensic marking. A draft of an “official” set of recommended practices was posted. It is posted lower on this page.

The discussion has been focusing on:

1. 1)It is not necessary for the FM Vendor to recover the FID, it could be a FM Recovery Service Provider (Sounds good to me-corrections made to document below... Jerry)
   

2. 2)A fair amount of discussion on the allocation of the 19 bits and the subdivision of these bits. I believe the allocation is outside the scope of ISDCF it is up to the FM provider to do the allocation. 
   

DRAFT

Inter-Society Digital Cinema Forum
(ISDCF)

Forensic Mark Recommendations
30 November 2007

The following recommendations are designed to facilitate the identification of the source location and equipment following the recovery of a Forensic Mark ID from marked content.

The recommendations are based on the process described in Annex A and leverage the existing mapping between playback equipment and locations. This mapping is used by Fulfillment Entities to generate Key Delivery Messages (KDM) and is populated using Facility List Messages (FLM), which lists the playback equipment installed in a particular location. By extending the FLM to include the Forensic Mark ID associated with the playback equipment, the same mapping used to generate KDMs may be used to trace the source playback equipment and location from marked content.

Recommendations

First recommendation. In order to ensure that a recovered Forensic Mark ID can be reliably traced to a single Image Media Block, each Forensic Mark Technology Vendor should (a) select a unique Algorithm ID in the form of a URI, where the Algorithm ID uniquely identifies the technology employed, and (b) allocates a unique Forensic Mark ID to each Image Media Block that incorporates the identified forensic marking technology. The same Forensic Mark ID may be used by more than one FM Vendor, but each FM Technology ID and Forensic Mark ID pair must be globally unique.

In the case where the manufacturer of the playback equipment offers the choice to its customers of using one of multiple FM technologies, having in mind that a single Forensic Mark ID could be assigned to an Image Media Block independently of the Forensic Marking Technologies offered by the IMB manufacturer, it is the responsibility of the chosen FM vendors and the Image Media Block manufacturer to coordinate Forensic Mark ID allocation accordingly.

Second recommendation. In order to ensure that Forensic Mark IDs and Algorithm IDs can be made available to Fulfillment Entities, Image Media Block manufacturers should make available the Forensic Mark ID and Algorithm ID associated with each Image Media Block to the end user, whether exhibitor or deployment entity.

Third recommendation. In order to ensure that Forensic Mark IDs and Algorithm IDs can be communicated to Fulfillment Entities by exhibitors or deployment entities, the Facility List Message should include both the Forensic Mark ID and Algorithm ID associated with each Image Media Block device listed.

Annex A – Forensic Mark Process

1. An Image Media Block is manufactured.

1.a. The Image Media Block is assigned a unique certificate.

1.b. For each Forensic Marking Technology it implements, the Image Media Block is assigned a unique Forensic Mark ID from a block of Forensic Mark IDs provided to the Image Media Block manufacturer by the FM Vendor. The internal bit allocation of the Forensic Mark ID is left to the FM Vendor but the Algorithm ID and Forensic Mark ID pair is globally unique.

1.c. The Image Media Block stores a copy of the certificate, Forensic Mark ID and Algorithm ID.

2. The Image Media Block is installed at a location.

3. A Fulfillment Entity wishes to distribute Content to Image Media Blocks installed at a particular location, as instructed by a Studio.

4. The Certificate, Algorithm ID, Forensic Mark ID and Location of the Image Media Block are retrieved from the Image Media Blocks at the location and communicated to the Fulfillment Entity using the FLM.

5. The Fulfillment Entity generates a KDM for each Image Media Block based on its Certificate and Location, and records the Forensic Mark ID and Algorithm ID.

6. At a later time, the Studio takes possession of misappropriated content and sends it to all FM Vendors or a FM Recovery Service Provider.

8. One FM Vendor or the FM Recovery Service Provider recovers the Forensic Mark ID from the content using a specific Forensic Marking Technology.

9. The FM Vendor or the FM Recovery Service Provider sends the Forensic Mark ID to the Studio

10. The Studio forwards the Forensic Mark ID to the Fulfillment Entity(ies) responsible for distributing the content.

11. The Fulfillment Entity(ies) consults its records and determines the Image Media Block and Location associated with the Forensic Mark ID.

12. The Fulfillment Entity communicates this information to the Studio.