This document discusses security issues related to moving from single cloud to multi-cloud environments. It first provides background on the increased use of cloud computing and the privacy and security concerns organizations have in using single cloud providers. It then discusses the trend toward multi-cloud/inter-cloud environments to address issues like availability and potential insider threats. The document examines research on security issues in single and multi-cloud environments and outlines the objective to automatically block attackers and securely compute data across clouds.