Résumé : This chapter advocates the convergence between Access Control (AC) models focusing on the granularity of sharing and Digital Right Management (DRM) models focusing on conditional authorizations and obligations. The convergence is also expected in terms of control enforcement considering that both AC and DRM models must be equally protected against any form of tampering and piracy. We capitalize on the democratization of powerful secure chip platforms (e.g., smart cards, secure USB dongles) which can be plugged in a variety of client devices (PC, PDA, cell phones, consumer electronics) to design a new architecture of a trusted access and usage control system. The benefits of the proposed architecture are exemplified in two different contexts: a fair DRM scenario and a healthcare scenario.