Smart Spaces are composed of heterogeneous sensors and devices that collect and share information. This information may contain personal information of the users. Thus, securing the data and preserving the privacy are of paramount importance. In this paper, we propose techniques for information security and privacy protection for Smart Spaces based on the Smart-M3 platform. We propose a) a security framework, and b) a context-aware role-based access control scheme. We model our access control scheme using ontological techniques and Web Ontology Language (OWL), and implement it via CLIPS rules. To evaluate the efficiency of our access control scheme, we measure the time it takes to check the access rights of the access requests. The results demonstrate that the highest response time is approximately 0.2 seconds in a set of 100000 triples. We conclude that the proposed access control scheme produces low overhead and is therefore, an efficient approach for Smart Spaces.