Nowadays the concept of ”pervasive computing” is fully deployed in smart environments to bring more comfort and to allow an easy access to services for users. Due to this fact it is essential to reconsider some security service delivery in smart environments. The authentication service is tightly related to the user and must imperatively take into account his capacities, his preferences and his environment, to be efficient for dependent people. In this paper we propose a new architecture able to provide an intelligent authentication based on modelisation parameters of both the environment and the user profile which are used to build an authentication strategy.