Protection of DRM agent codes

Abstract

In most existing digital rights management (DRM) technologies, the DRM agent, or DRM client, contains the content protection mechanisms applied to the system. However, the DRM agent that runs at the consumer side is often exposed to reverse engineering to compromise DRM agent or to obtain the secret license information kept at the DRM agent. In this paper, we propose an algorithm to protect against the reverse engineering of DRM agent codes and thus to protect the inside workings of the DRM agents. Our algorithm is based on self-modifying code and control flow flatten techniques. And after applying our algorithm, the agent software becomes hard to be analyzed by the attacker, which can be seen from the experimental results. © 2009 Springer-Verlag Berlin Heidelberg.