A method for certifying the identity of a user offering a service (USER2), said method using an identification server (SERV) and comprising: - a reception step in which the identification server (SERV) receives, from a first device belonging to a first user (USER1), identification data regarding a second user (USER2) who corresponds to the user offering a service, - a comparison step in which the identification server (SERV) compares the identification data with certified identities contained in an identity database of the identification server (SERV), - a processing step in which, when the identification data received is determined by the identification server (SERV) to match a certified identity of the identity database, the identification server (SERV) retrieves information (INF DEV3) regarding a third device belonging to a third person corresponding to said certified identity, said information (INF DEV3) regarding the third device being stored in the identity database, - a generation step in which the identification server (SERV) generates an identification code adapted to confirm the identity of the second user (USER2) and sends said identification code to both the first device and the third device for further display of the identification code by said first and third devices, and - a verification step in which the first user (USER1) verifies that the second user (USER2) has received an identification code on a second device belonging to said second user (USER2) and if so, that the identification code received by the second user (USER2) on the second device corresponds to the identification code received on the first device, in which case the second device corresponds to the third device. - a reception step in which the identification server (SERV) receives, from a first device belonging to a first user (USER1), identification data regarding a second user (USER2) who corresponds to the user offering a service, - a comparison step in which the identification server (SERV) compares the identification data with certified identities contained in an identity database of the identification server (SERV), - a processing step in which, when the identification data received is determined by the identification server (SERV) to match a certified identity of the identity database, the identification server (SERV) retrieves information (INF DEV3) regarding a third device belonging to a third person corresponding to said certified identity, said information (INF DEV3) regarding the third device being stored in the identity database, - a generation step in which the identification server (SERV) generates an identification code adapted to confirm the identity of the second user (USER2) and sends said identification code to both the first device and the third device for further display of the identification code by said first and third devices, and - a verification step in which the first user (USER1) verifies that the second user (USER2) has received an identification code on a second device belonging to said second user (USER2) and if so, that the identification code received by the second user (USER2) on the second device corresponds to the identification code received on the first device, in which case the second device corresponds to the third device.