Thanks to pervasive environment, users can remotely have access to various resources and services within their public or private living space. Consequently, several security and privacy issues are raised especially due to the wireless access used to get services and to the privacy aspect that could be involved. To securely deploy these services in multiple smart spaces, we propose a secured service provision mechanisms based on trust relationship between involved actors (service platform and mobile nodes). These mechanisms integrate a service discovery as a preliminary step to build a secured channel between a user (U) and a Service Platform (SP). A trust model is used to interconnect several users with a service platform based on recommendation and trust management