In this short paper we describe the architectural concept of a Citizen Digital Assistant (CDA) and preliminary results of our implementation. A CDA is a mobile user device, similar to a Personal Digital Assistant (PDA). It supports the citizen when dealing with public authorities and proves his rights— if desired, even without revealing his identity. Requirements for secure and trusted interactions in e-Government solutions are presented and shortcomings of state of the art digital ID cards are considered. The Citizen Digital Assistant eliminates these shortcomings and enables a citizen-controlled communication providing the secure management of digital documents, identities, and credentials.