Abstract: The present invention relates to a method for establishing a shared secret between a first and a second device (1, 2) without any shared trust between the first and second device, for the use of services provided by a service provider (3?) to a user (4) of the second device (2), where the user (4) of the second device (2) is identified (11) by the service provider (3), the second device (2) request (12) and receive an activation code from the first device (1), the user (4) of the second device send (13) the activation code to the service provider (3), the service provider (3) send (14) the activation code to the first device (1), the first device (1) confirm the activation code and generate and store the shared secret (15), the first device (1) generate a reference to the shared secret and transfer (16) the reference and shared secret to the second device (2), the first device (1) transfer (19) the reference to the service provider (3), and the service provider (3) store (110) the reference and associate the