The advent of digital media technology and the emergence of Internet-based content have raised the bar for what consumers expect from in-home entertainment. With more media and programming available than ever before, people want to be able to enjoy on-demand videos, cable TV programs and music anytime on their favorite device, whether it is a PC, a smart phone or digital video recorder connected to a TV.
The growing popularity of wired and wireless home networking is raising expectations even further. As people build digital libraries of movies, video clips, songs and TV shows, they naturally expect to use this wealth of content on their connected devices. The essential premise of the digital home is the ability to easily enjoy your content on your favorite devices wherever and whenever you desire.
Additional consumption by more people in more places has positive revenue implications for device manufacturers, service providers and content rights holders. But as promising as these trends may be, the convergence of digital media technology and IP-based home networking may never reach its true potential if content owners and service providers cannot reliably protect premium digital content from unauthorized use.
Reliable content protection is essential if individual artists, movie studios, TV production companies, broadcast networks and service providers are able to have a sustainable and expandable business with these emerging digital home usage models. These usages include video on demand on multiple devices, sync-and-go viewing with portable media players, location-free TV viewing over the Internet, and the deployment of digital media servers in the home.
Content owners must also recognize that digital rights management (DRM) could impose restrictions that dampen the enthusiasm of consumers. It is crucial to strike the appropriate balance between content protection and usability.
The key question comes down to this: how can the digital content industry achieve the benefits of end-to-end content protection to benefit copyright holders, without adversely impacting consumer expectations for device interoperability and content portability?
Digital Transmission Content Protection (DTCP) and its latest iteration, DTCP-IP, provide a coherent technical and licensing framework that meets the requirements of the CE industry and the expectations of consumers for choice and control over a new world of digital media.
Consumers love their digital content and also want the freedom to move it from PCs and set top boxes to their DVRs, handheld players, mobile Internet devices and phones – and the industry has responded in a couple of basic ways.
Some vendors have focused on proprietary end-to-end content protection solutions to control the use of protected digital audio and video – all the way from the source to the endpoint device. While such solutions can be effective, they may not support portability of content among a consumer’s devices, or provide the flexibility needed for innovative third-party solutions.
As an alternative, the industry has developed a plethora of point solutions for content protection. Within the home, these multiple solutions come together to form an overall chain of content protection. While individual links in such a chain may be strong by themselves, the chain must also be able to ensure continuity of protection from the point of access to the ultimate client device – as content is acquired, transmitted, stored and consumed on multiple connected devices.
The growing number of content protection technologies underscores the need for a comprehensive architectural framework to ensure the individual links in the chain form an interoperable whole. Without such an architectural framework, there may be inconsistencies, gaps, and technology conflicts that limit the effectiveness of content protection, or frustrate consumer attempts to record and share digital authorized content.
Intel’s long-term involvement in the development of such a content protection framework is motivated by four fundamental goals:
- Help the industry meet consumer expectations for broader choice, flexibility and content portability
- Work with leaders in content production, content delivery and CE products to encourage the widespread adoption of new usage models based on digital home networks
- Develop consistent technical and licensing mechanisms to ensure reasonable protection and fair compensation for copyright holders and help maintain sustainable business models
- Support the development of simple, inexpensive and transparent solutions that help the industry meet the growing demand for compelling and innovative products
It is important to recognize at the outset that no content protection technology is perfect or invulnerable. Creating a protected digital environment involves a combination of technical and legal mechanisms designed to protect content against unauthorized use.
Technical mechanisms are primarily designed to keep honest people honest, by preventing unsophisticated or casual attempts to circumvent the content protection technology. At the opposite end of the spectrum, no content protection technology can protect against the professional hacker. Other mechanisms are in place to address these issues. These include licensing, enforcement of intellectual property rights and anti-circumvention laws which may be effectively employed against professional operations with assets and distribution channels.
This two-pronged approach continues to provide a powerful yet practical basis for open architectures for content protection designed to block circumvention, while accommodating consumer expectations.
Commercial viability is the key to success. This means that content protection mechanisms must be cost-effective for the industry. Intel has worked diligently to bring content protection technologies to market based on a low-cost licensing model. We have also worked to develop flexible hardware and software implementations that do not unduly impact the system resources of devices. Implementation costs should be kept low, so consumers are never asked to pay more for content protection.
Compared to proprietary end-to-end solutions, an open architectural framework for content protection has the advantage of enabling a variety of content delivery systems and home networking content protection technologies to peacefully co-exist within the same protected environment. These open architecture content protection technologies provide security through cryptographic protocols and end-to-end content protection and device interoperability through licensing chains and compliance rules.
The technical mechanism for content protection is based on encryption, and it has four essential elements:
- Authentication verifies that products comply with licensing conditions
- Encryption prevents unauthorized access to content by limiting decryption to authenticated products
- Usage states include information that specifies how the content may be used
- Renewability extends the viability of the content protection solution
Access to cryptographic keys and other information, as well as the use of the technical specifications, is subject to a license agreement. The license provides a way to legally enforce the conditions under which such access is granted, including rules governing any subsequent storage and transmission of content.
Elements of the license agreement include:
- License grants provided to adopters for the purpose of implementing the technology consistent with specifications, compliance rules and other license terms
- Ability to make specification changes by the licensor to improve the integrity, security and commercial viability of the content protection solution
- Third-party enforcement to enable content owners to exercise certain rights under the agreements to protect their valuable content
- Revocation processes that establish conditions and a process under which keys and/or certificates may be expired or revoked
- Compliance rules that define the standard which must be met by the implementation of content protection technologies, in addition to rules for the storage and transmission of protected content
- Robustness rules to discourage discovery, circumvention, reverse engineering or other modifications to the implementation of a content protection technology in order to gain access to highly confidential keys, certificates or other secrets
An open architecture for content protection supports a chain of solutions for protecting licensed digital content as it is transferred, stored, managed and accessed on connected devices. A variety of technologies are available to meet the requirements of specific devices and applications. Figure 1 shows one example of an end-to-end content protection chain.
Figure 1. One example of a digital content protection chain.
Figure 1 depicts only one of many possible configurations on a home network. In this example, Digital
Transmission Content Protection (DTCP) defines a cryptographic protocol for protecting entertainment
content from illegal copying, intercepting and tampering as it traverses bidirectional digital interfaces.
Content Protection for Recordable Media (CPRM) is an industry specification for protecting digital
content on portable media formats such as recordable DVDs and SD Memory Cards. High-Bandwidth Digital
Content Protection (HDCP) is a specification for protecting digital entertainment content over
High-Definition Digital Multimedia Interface (HDMI) and Digital Visual Interface (DVI) connections.
Content protection chains may include many other content protection technologies, including Advanced
Access Content System (AACS) for content stored on next generation of pre-recorded and recordable
optical media.
Digital Transmission Content Protection (DTCP) was created by five companies – Hitachi, Intel, Matsushita, Sony and Toshiba – also known as the “5C”. It defines a cryptographic protocol for protecting entertainment content against unauthorized copying or tampering as it moves across bi-directional digital interfaces such as wired and wireless IP-based home networks, IEEE 1394 and USB.
The benefit of DTCP framework is its openness and flexibility:
- DTCP is designed to enable the use of multiple commercial technologies for end-to-end protection of content
- Content can be received from multiple sources, including broadcast, broadband and pre-recorded media
- Protected content can be transmitted to a variety of devices connected on a home network
- DTCP is designed to be transparent to consumers
Because it does not limit performance or quality, DTCP allows home users to experience high-quality digital pictures and sound. The framework also provides the flexibility to support a variety of content delivery modes and business models. DTCP enables transport of protected commercial content and promotes network interoperability with low technological overhead.
DTCP helps to overcome the traditional limitations of DVD players and digital cable and satellite set top boxes. These devices may include display-only digital connections such as HDMI that were not designed to permit digital recording or home networking or lower-quality analog connections.
Realizing that consumers expect to use their DVRs and other digital recording technologies to move content freely around their homes, the 5C licenses the DTCP Specifications through the Digital Transmission Licensing Administrator (DTLA). The DTLA has the necessary legal agreements for adopters who wish to implement the DTCP Specification. One feature of the license offered by the DTLA is to define reasonable and customary use of content, including recording digital copies to support emerging usage models.
DTCP makes it possible for consumers to enjoy high-quality digital video and audio throughout the home — including making personal digital recordings of content, as permitted by the content owner. DTCP technology is also ideal for PC-based media servers and other networked storage devices that make personal digital libraries accessible on any connected device, anywhere in the home.
DTCP has evolved to become the common denominator for multiple digital rights management (DRM) and content protection solutions that are used to bring content into the home, including content delivered to complex devices such as PCs, advanced digital set top boxes and DVRs.
As wired and wireless Internet Protocol (IP) networks grow in popularity in homes, and as the Internet expands to deliver new broadband content, consumers will begin to use their TVs to access growing catalogs of IPTV programming, IP-based interactive services and applications.
DTCP-IP is the extension of DTCP technology to support these IP-based usage models. It provides an ideal way to protect content and maintain usage policies as content is exchanged between connected devices.
In the summer of 2007 CableLabs and the DTLA jointly announced that CableLabs has approved DTCP-IP technology for protection of cable content using IP for both unidirectional and bidirectional digital cable products. DTCP-IP will enable cable subscribers to access cable programming, video on-demand and HD video on a wide variety of CE devices, mobile Internet devices and PCs on their digital home networks.
The Internet represents a disruptive technology that will make digital content from many sources available to consumers on a spectrum of connected devices in the home. As more devices are developed to receive, store, exchange and play content, we expect consumers to adopt many new usage models involving recording and sharing digital video, audio, IPTV programs, games and other licensed content delivered by service providers and digital broadcasters.
These usage models hold tremendous promise for the CE industry, IT professionals, content owners, and service providers, but realizing their true potential will require an open architecture for creating a digital content protection chain capable of linking the multiplicity of devices and content protection solutions.
DTCP and its latest iteration, DTCP-IP, provides a coherent technical and licensing framework that meets the requirements of the CE industry and IT for a lightweight and inexpensive software-based solution that enables third-party devices and content protection solutions to work together. By enabling broad use of licensed content, DTCP-IP helps meet the expectations of consumers for choice and control over a new world of digital media.
At Intel we believe that a reasonably protected digital environment is essential if future digital home usage models and business models are to meet their true potential. The protected environment should address the interests of intellectual property rights-holders, while providing consumers with the flexibility, content portability and freedom of choice they desire. We believe that markets, not mandates, stimulate innovation and deliver the most consumer value.