This article describes a new approach to creating and securing ubiquitous augmented reality (AR) systems. Creation of AR presentations in distributed environments, where AR presentation can be dynamically composed at runtime based on distributed data sources and the usage context, and where new services can be dynamically added by various service providers, raises security concerns related to both service access control and users’ privacy. To address this challenge, a generic architecture for deployment of ubiquitous AR services and an application-layer security protocol, which enforces usage of AR content according to semantically described usage policies, are proposed.