With the arrival of digital television, and especially high definition, security requirements are becoming even more stringent. In some places, such as the Nordic countries, it is already mandatory to encrypt all transmissions when broadcasting digital television in communities or private networks. In other countries, regulations are not as demanding, or are still evolving, but the following trends are becoming clear:- Require that all high-definition content from paid platforms be encrypted all the way to the television.
- Require that protected content have invisible marks (“digital watermarks” or watermarking) that allow its origin to be identified in case it is leaked to unauthorized distribution channels (e.g., the internet).
These restrictions pose a significant technological challenge for the professional television installer and their solution providers, as they will find themselves having to carry out installations of a complexity previously reserved for large cable networks.
Below we present the new security technologies that we will need more and more frequently in collective television installations.
Header encryption.
Conditional access systems are divided into those designed for broadcast environments (e.g., digital satellite or terrestrial TV) and those designed for IP environments (e.g., IPTV, DOCSIS, or WebTV networks). The main difference between the two is the availability of a return path that allows for verification of the security system's integrity.
These systems, common in large TV distribution networks, were previously unknown in hotels and residential communities. Digitization and the increasing availability of HD content necessitate the introduction of encryption systems that keep the video secure all the way to the television screen. For broadcast networks, there are already affordable systems, such as Philips' VSecure, which integrates decryption directly into the television itself (thus eliminating the need for a separate set-top box).
Watermarking Systems:
In addition to installing an encryption system, content providers may also require the implementation of watermarking systems to enable traceability in the event of illegal distribution of content. These "watermarks" must be imperceptible to the viewer yet robust enough to withstand typical video editing operations, such as:
- Recording with a digital camera.
- Transcoding to reduce the recording size.
- Changing the video format (for example, converting from MPEG video to Windows Media).
Author:
David Domínguez, Head of Projects at the Multimedia Unit of Ikusi.
