With the expansion of Web servers and cloud infrastructures, collaborative Web applications are increasingly used. For instance, the e-learning is a field where students, tutors and professors share remote electronic resources and processing. Nevertheless, interference between information may occur that is data can illicitly flow to not authorized users either explicitly or implicitly. Therefore, one challenge in collaborative applications is to ensure an end-to-end security preserving user's privacy and verifying information integrity. We propose a practical solution to secure standard Web servers and isolate user's information. A use case of a classical meeting application, typically used in e-learning environment, shows the efficiency of our approach.