This paper addresses the specification of security modules in a Mobile Digital Rights Management (DRM) approach with a focus on copy detection mechanisms. The presented DRM approach aims at enhancing the latest DRM standard of the Open Mobile Alliance (OMA). In particular, we present a completed DRM infrastructure, introduce additional entities for billing purposes, and apply techniques to hamper unauthorised decryption and to protect the copyright of the digital distributed content by means of watermarking and digital fingerprinting techniques.