Abstract The necessity to improve security in a multi-cloud environment has become very urgent in recent years. Although in this topic, many methods using the message authentication code had been realized but, the results of these methods are unsatisfactory and heavy to apply, which, is why the security problem remains unresolved in this environment. This article proposes a new model that provides authentication and data integrity in a distributed and interoperable environment. For that in this paper, the authors first analyze some security models used in a large and distributed environment, and then, we introduce a new model to solve security issues in this environment. Our approach consists of three steps, the first step, was to propose a private virtual network to secure the data in transit. Secondly, we used an authentication method based on data encryption, to protect the identity of the user and his data, and finally, we realize an algorithm to know the integrity of data distributed on the various clouds of the system. The model achieves both identity authentication and the ability to inter-operate between processes running on different cloud’s provider. A data integrity algorithm will be demonstrated. The results of this proposed model can efficiently and safely construct a reliable and stable system in the cross-cloud environment.