With the advent of the World Wide Web and the emergence of e-commerce applications and social networks, organizations across the world generate a large amount of data daily. This data would be more useful to cooperating organizations if they were able to share their data. Two major obstacles to this process of data sharing are providing a common storage space and secure access to the shared data. In this paper we address these issues by combining cloud computing technologies such as Hive and Hadoop with XACML policy based security mechanisms that provide fine-grained access to resources. We further present a web-based application that uses this combination and allows collaborating organizations to securely store and retrieve large amounts of data.