The research community and some commercial organizations are beginning to develop architectures, technologies, and standards to support the integration of multiple cloud systems (Inter-Clouds). In Inter-Cloud systems, security is one of the most important challenges, because of the need for dynamic sharing, federation, and collaboration across multiple clouds. Security in this type of systems relies heavily on the establishment of trust among the involved components. It can be harder to achieve security if a comprehensive and detailed architecture is not developed; the lack of a common architecture slows down the process of Inter-Cloud adoption and has a negative impact on the process of making these systems more secure. We propose to use patterns in order to achieve Secure Inter-Cloud Architectures. Patterns are tools of great value because they provide a better understanding of the functional aspects and can be complemented with security patterns to achieve a Secure Inter-cloud Architecture. In this work, a federated Inter-Cloud pattern is presented as a first step in to the process of developing a Secure Inter-cloud Reference Architecture. Threat analysis and security patterns will be added to this pattern for that purpose.