TEE: A Secure Platform on which to Build Content
Gain an insight into Fox's premium content protection and the role of TEE standardization.
How has premium content evolved over recent years?
Premium content has changed: ‘Premium content’ used to refer to DVD, then Blu-ray, while today it can include a number of technologies such as ultra HD. There has always been a need to protect premium content. In the past, however, this has not been very successful; DVD and similarly Blu-ray have both been compromised and illegally copied. The fundamental problem the industry has always experienced when it comes to content protection is that it is based on non-secure platforms. The TEE changes this: it provides a more secure platform on which to build our content.
Even though TEE technology exists, what’s really important to Fox is for the TEE to be standardized and certified by a recognized industry association such as GlobalPlatform.
Why is it important to Fox to have a standardized and certified TEE?
The lack of a standardized and certified TEE is resulting in a fragmented market in which players are developing and implementing TEEs in their own way, without oversight. This is causing a problem for content providers as we now have to ‘trust’ that TEEs are implemented correctly and are solid and secure. We have no industry standard or ‘approval stamp’ to enable us to recognize when a TEE meets a specific standard.
During GlobalPlatform’s TEE Conference, Spencer Stephens, CTO of Sony Picture Entertainment, discussed the concept of a ‘trusted’ TEE. I believe this is a great way to explain what the industry requires and also describes the work GlobalPlatform is undertaking to standardize the technology.
It is important for us to align our work with what GlobalPlatform is doing. We don’t want a situation where Fox is doing one thing in regards to TEE certification and GlobalPlatform is doing another. We work closely with many GlobalPlatform members including ARM and Trustonic to ensure we remain aligned with the association’s activity in this space.
Why is the TEE important for premium content protection / what value will the technology deliver?
The name ‘trusted’ is there for a reason; the TEE provides a route of trust and creates a secure operating environment. It enables content providers with a means to trust what is happening with our content. The TEE needs to evolve to deal with the decryption of content all the way through to the secure video path. This is an area GlobalPlatform is in the process of addressing; without protecting the video path the TEE only does a small part of the job protecting content.
What is the secure video path?
This is an area where content is decrypted and decompressed. The content industry takes advantage of compressed content on a disc to save space; this is then decompressed in the video path so that we can render the video and add graphics and menu options, for example. This all has to be done securely because if not, our content will be compromised and illegally copied. This entire path has to be protected by the TEE to ensure that at any point content is protected from an attack.
What are Fox’s premium content protection efforts today?
There are three main areas we are focusing on at the moment:
- The development of the Secure Content Storage Association (SCSA) group. This association, created by Fox, Warner Bros., Western Digital and SanDisc, will look at the secure storage and secure playback of our content. Within the secure playback mode, we are also developing Robustness Rules around the TEE. A Robustness Rule specifies the requirements that must be adhered to on any device before it can host our content. We hope that in the future, GlobalPlatform will be able to certify our Robustness Rules, however, for the moment, we need to have some form of guidelines in place which specify what is required on a devices in order to host our premium content.
- Advancing our work with Motion Picture Laboratories (MovieLabs). Fox is working with MovieLabs (a non-profit research and development joint venture started by the six major motion picture studios) to create a document which communicates our content protection requirements. The initial version of this document is now available.
- Blu-ray premium content requirements. As Fox distributes much of its premium content through Blu-ray we are constantly trying to advance Blu-ray from a premium content standpoint.
There are of course many areas we are working on to improve delivery of our premium content, and one of the key things is for us to ensure that it is done securely. For Fox, there are two considerations when it comes to security:
- Protecting the content we have.
- Enabling different business models. For example, allowing a consumer to have our content before we enable them to watch it. If Fox was able to secure its content and specify when a consumer could access it, this might enable different business models.
How do Fox’s Robustness Rules align with GlobalPlatform’s standardization work?
The work GlobalPlatform is undertaking to standardize and test the TEE is already included as requirements within our Robustness Rules. The problem we have at the moment is that we don’t have the capabilities, experience or bandwidth to check that every implementation complies with the criteria set out in our Robustness Rules. If the industry has a standard, recognized TEE, this will enable us to easily understand which TEEs are able to securely host our content.
What benefits will standardizing the TEE bring to the marketplace?
It will increase confidence in the TEE. There are many different implementations and the market is very fragmented right now. Standardizing the TEE will reassure all stakeholders in the industry that we can trust the TEE and it has been deployed correctly. The term ‘trusted’ TEE is a good way to describe what GlobalPlatform is bringing to the market.
What are your short and long term predictions for premium content protection and the role of TEE in protecting the content?
Fox will always have a requirement for its premium content to be protected on devices. As the threat landscape evolves and new attacks come to market such as side channel attacks, I believe we will need to respond to these attacks and add renewability to the software that is controlled by the content provider.
From the perspective of the TEE, the key areas that need to evolve are the standardization and certification that GlobalPlatform is undertaking. Fox needs to contribute to the work of GlobalPlatform to ensure the protection of a secure video path within its work efforts. The association needs to continue working with its members to reach its end goal of standardizing the TEE.
What the market needs to understand is that the pirates we are trying to protect our content from are resilient – they don’t take ‘no’ for an answer! We need different barriers and levels of protection to combat these threats; the TEE is not the panacea, the TEE is one tool to help combat piracy.
How important are events such as GlobalPlatform’s TEE Conference in supporting the growth and standardization of TEE technology?
Based on the questions received throughout the conference I would say very important. The concept of the TEE was challenged and questioned during the event, indicating there is still confusion in the industry and a need for further education.
Documents such as the one developed by MovieLabs (as mentioned in question five) play a vital role in communicating the content providers’ requirements for the TEE. GlobalPlatform’s TEE Conference brought together stakeholders from different markets and provided a platform for knowledge and information to be shared and for each market to understand the relevance of the TEE and how it can be utilized for a wide variety of use cases.
Fox looks forward to working with GlobalPlatform and its members to advance its efforts in establishing a standardized and certified TEE, which is workable for each market sector.
By: Ian Harvey, Senior Vice President, Advanced Technology, Fox Filmed Entertainment