Abstract
The adoption of cloud computing becomes hampered by the emergence of security problems. We aim in this paper to define a framework which clarifies the concepts of security in a cloud environment and can afterwards check a number of security properties. To achieve this objective, we propose a three-level approach: Modeling, Specification and Verification. In the first step, we propose an agent based modeling of cloud architecture in order to leverage the capabilities of software agents and consequently to reduce complexity. In specification step, we formally specify the concepts evoked in the modeling step and enrich them by others related to security. In the last step, we proceed to verify the security level in cloud environments in order to better control their entities behaviour.