Cloud computing has become the focus of attention in the computing industry. However, security concerns still impede the widespread adoption of this technology. Most enterprises are particularly worried about the lack of control over their outsourced data, since the authentication and authorization systems of Cloud providers are generic and they cannot be easily adapted to the requirements of each individual enterprise. An adaptation process requires the creation of complex protocols, often leading to security problems and “Lock-in” conditions. In this paper, the authors present the design of a lightweight access control solution that overcomes these problems.