David Ramirez
Senior Manager, Global Practice, Security & Business Continuity
Lucent Worldwide Services

In the past few months, there have been countless articles written on the promise of Internet Protocol Television, more commonly known as IPTV. Service providers and network providers alike are eagerly eyeing a potentially fresh new revenue stream. While content providers consider the possibilities of a new delivery mechanism that offers a less costly delivery channel for niche and mainstream content.

However as with any kind of IP-network, IPTV opens up networks to new risks that are not common in the traditional broadcasting or cable television infrastructure. It may also open a new risk for service providers who are used to carrying more utilitarian voice or data traffic. By carrying premium content channels carriers must insure that the content is being protected from unauthorized access and modification.

For years the satellite television industry has been combating access fraud. Every time the industry has countered with better security measures hackers have managed to find alternative ways to break the safeguards.

In the existing closed system broadcast model, fraud is present but not substantial. However as the industry moves towards a model that convergences IP technology with video technology the level of threat will increase dramatically as well. In emerging models IP video will be transferred to set top boxes as well as computers increasing potential hacker attacks. Using simple software modification hackers are able to break the encryption systems and other security measures to capture and potentially redistribute the content using peer-to-peer networks.

There are currently three primary types of technologies used to protect video applications: intellectual property (IP) rights, content protection systems, conditional access systems and digital rights management.

• Content Protection Systems (CPS) - In this technique content is transmitted across the network in an encrypted form to help protect against theft or unauthorized access. Content Protection Systems ensure that content is only viewed by authorized subscribers. Even if an intruder intercepts the communication, the content would be encrypted and therefore worthless. An important security issue with CPS is the handling of key management processes, including how and how often keys are exchanged between parties.

• Conditional Access System (CAS) - CAS helps ensure that only authorized subscribers have access to the content, creating a safeguard against theft of service. Many cable operators already use CAS to control access to content. Because of its popularity, CAS has evolved from the use of simple frequency shifts and electronic noise to full-blown content encryption.

• Digital Rights Management (DRM) - The growth of peer-to-peer networks shows that digital content can be effortlessly traded on the Internet. DRM systems focus on managing the specific use and distribution of content by individual subscribers. Initially technology providers have implemented solutions that had weak DRM control. However content owners have started pushing DRM systems with strong controls that reduce the risk of unauthorized access to content.

There are currently two basic options for content delivery using IP Video: Video on Demand (VOD) and broadcast. Each approach has it own security and DRM requirements. For VOD it is recommended that content is segmented and encrypted using a symmetric key. The key can be changed several times during the movie to increase protection. Each set top box has the subscriber's private key and the VOD server sends the encrypted content and the encrypted symmetric keys to the set top box for decryption and playback.

Broadcast content follows a very similar process. Content is encrypted at the source with a symmetric key. The set top box send a request for the current content key and the content server sends an encrypted symmetric key to be used by the set top box to retrieve the contents.

Content owners are demanding relatively strong encryption for their data, including the implementation of Advanced Encryption Standard (AES). This will probably shift attacks from content to the end point and the transport layer.

Obviously there are a number of security measures that can be employed in an IP network. One approach that is gaining industry recognition is a comprehensive security framework created by Bell Labs and later adopted by the International Telecommunications Union (ITU). The ITU's X.805 standard can be used to review security threats in an IP TV network.

Some threats to this type of network include:

• Denial of service attacks and worm propagation
• Network infrastructure attacks
• Trojan horse programs and customers theft of service
• Self-provisioning infrastructure attacks
• Billing infrastructure attacks
• Intellectual Property (IP) theft

The X.805 standard has eight security dimensions that cut across the management control and end-user security planes of the x.805 framework. Each plan has its own underlying infrastructure, services and applications. This encompasses everything from the IP backbone through the vide application middleware to the video head office and finally the set top box.

The eight dimensions include:

• Access control
• Authentication
• Non-repudiation
• Data confidentiality
• Communications security
• Data integrity
• Availability
• Privacy

Each of these dimensions can be applied to an IP TV service and will yield different security recommendations. For a full analysis of this process take a look at our white paper. The framework provides a thorough analysis of the threats and potential security risk facing a network. It provides a detailed plan of attack for network operators that limits network risks.

Despite the ingenuity of hackers and the potential vulnerabilities associated with any new technology, secure IP TV can be a reality. But just as is the case with any new technology as IP TV continues to evolve its security technology needs to evolve as well.

Constant vigilance and network analysis is required as hackers continue to circumvent security measures. With careful attention to security efforts and thorough planning much of the security risk can be mitigated. With its security issues adequately addressed, IP TV is poised to become an exciting new service for businesses and consumers.

Ramirez was born in Colombia and has been involved with Information Security for the past ten years. He began his career as a networking specialist. Subsequently he joined a consulting company managing the Information Risk Management practice implementation where he was involved in risk assessments for more than 80 companies. In 2002 David transitioned to a UK Risk Management company as part of their new Information Security division. In this period he was involved in security projects for many major financial institutions around the world. Ramirez recently joined the LWS Security & Business Continuity global practice, supporting the EMEA and CALA regions. David holds several industry certifications including CISSP, CISM and BS7799 Lead Auditor; and technology certifications including MCSE: Security and ISS Certified Engineer. Ramirez is in the last stage of his MSc on Information Security at Westminster University, London. He has been a speaker at several industry and security conferences, and has also published articles for several magazines, newspapers and websites.

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