Abstract-The emergence of cloud computing implies and facilitates managing large collections of highly distributed, autonomous, and possibly private databases. While there is an increasing need for services that allow integration and sharing of various data repositories, it remains a challenge to ensure the privacy, interoperability, and scalability for such services. In this paper we demonstrate a scalable and extensible framework that is aimed to enable privacy preserving data federations. The framework is built on top of a distributed mediatorwrapper architecture where nodes can form collaborative groups for secure anonymization and secure query processing when private data need to be accessed. New anonymization models and protocols will be demonstrated that counter potential attacks in the distributed setting.