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Digital Rights Management

Existing technical measures of copyright handling on digital content resp. services on end-user devices only registered moderate success, since most of the technical solutions can be totally controlled by the end-users due to the lack of appropriate protection in hardware and software. Experiences in the past have shown that hardware solutions (e.g. dongles) cannot be established because of their high complexity, incompatibility, insufficient security, and limited user acceptance. Moreover, a variety of these techniques were treated as trade secrets; a strategy which contradicts the cryptographic principals, because security should not rely on the secrecy of an algorithm but on the secrecy of a secret parameter (e.g., cryptographic keys). In spite of nondisclosure and legal threats by content providers, most of the methods have been broken in the past.

The PERSEUS DRM Platform

In contrast to existing insecure solutions, the PERSEUS security architecture can provide the required security properties to securely enforce licence agreements (see Figure 1).

Figure 1: Required services used to provide a reliable distributed enforcement of security policies.

Additionally to the basic security properties, the PERSEUS platform provides the following security properties required to enforce licenses in a distributed environment:

  • Content Manager: Ensures that digital content can only be accessed by applications and basic platform configurations that are trusted by the copyright holder to enforce the attached license. 
  • Installer: To allow DRM applications to enforce more complex licenses, the installer service allows them to verify properties of the underlying computing platform.
  • Trusted GUI: Guarantees integrity and confidentiality of digital content while it is displayed.
  • Trusted Storage: To be able to enforce stateful licenses (e.g., to allow n private copies), the internal state of licenses has to be stored such that reset attacks (overwriting the system state with an older one) does not violate security policies. More concretely, a secure platform has to ensure freshness of the storage used to store licenses.


Possible applications with short term potential are copyright protection, eLearning, eBooks, geographical information systems, as well as the area of Telematics in car navigation systems. Another field of application is the long-term high sale-expecting area of providing multimedia content, e.g., video and audio data. Here the platform will considerably complicate the unauthorised distribution of digital content. Certainly, this platform will build the basis for a pragmatic fair copyright protection. In this context, we are particularly interested in adapting the development of our platform to the concepts of fair use and first sale, which allow the private (e.g. one-time transfer) or non-profit (e.g., for educational purpose) usage of the content.