Method for authenticating a user, server, communication terminal and corresponding programs

The invention relates to a method for authenticating a communication terminal (TCP # 2) belonging to a user after an authentication server (Serva) connected to a gateway terminal (TCP # 1) by via a communication network. According to the invention such a method comprises: - obtaining, from said gateway terminal (TCP # 1), a data representative of an identity of the user; - configuration, by said authentication server (Serva) in a forward link transmission of data between said authentication server (Serva) and said user communication terminal (TCP # 2), via an interface predetermined data transmission of said terminal gateway (TCP # 1) and based on said data representative of an identity of the user; - transmitting, by the authentication server (Serva), the user communication terminal (TCP # 2), an encrypted data authentication check, via the data transmission link; - receiving, by the authentication server (Serva), from the user communication terminal (TCP # 2), an encrypted data against verification-authentication; - issuing a user authentication assertion when data authentication against-verification corresponds to said given check.