P2P data management systems provide a scalable alternative to centralized architectures. Their adoption, however, is limited by the lack of possibility to control the access on the resources stored in the system. We address the problem of access control for structured P2P systems and introduce various techniques to realize controlled access to the resources. We focus mainly on the case of non-mutable data objects, and however, some of the techniques introduced can handle the case of mutable objects straight away. In particular, we are interested to realize access control when the P2P data management system is used in a collaborative use case scenario. We explore the solution space elaborately and present solution approaches which realize the planned systems by either constructing independent networks or enforcing the access control at querying time or at replying time.