Method for mutual authentication between a terminal and a remote server by means of a third-party portal

A method for mutual authentication between (i) a user terminal cooperating with a security element as well as an application for registering with a service, and (ii) a remote server by means of a third-party portal, said remote server being suitable for providing said service, said method comprising:

• step i—after authenticating the user of said user terminal with said third-party portal, transmitting to said remote server by means of said third-party portal, signed information R, to enable said security element to be authenticated in said remote server, as well as a service request, wherein R comprises an identifier of said security element;
• step ii—authenticating said security element in said remote server, and if said security element is recognized:
• step iii—transmitting a value R′ signed by said remote server from said remote server to said application by means of said third-party portal, said value R′ including said s fined information R as well as a URL address making a response to said service request possible;
• step iv—transmitting a request for verification of said signed value R′ from said application to said security element;
• step v—verifying, in said security element, the signature of the remote server and whether the requested service has been granted by said remote server;
• step vi—establishing a secure connection with said remote server from said security element, and requesting that said requested service be executed.