Method of authentication of a user, a method implemented when said user accesses an online service, said online service being accessible in a server (SrvCMS) through an access terminal (TAcc), method comprising: - a step of dissemination, by the access terminal (TAcc), of a first piece of authentication data; - a step of obtaining by an authentication terminal (TAuth), of said first piece of authentication data; - a step of connection, by said authentication terminal (TAuth), to the server (SrvCMS) at a resource-location address (@LR) derived from said first piece of authentication data; - a step of obtaining, by the server (SrvCMS), of at least one piece of identification data (AuthD) for identifying said authentication terminal (TAuth); and - when said at least one piece of identification data (AuthD) for identifying said authentication terminal (TAuth) corresponds to piece of data pre-recorded (PrDAuth) in said server (SrvCMS): - a step of transmission, to said access terminal, of a piece of data representing a page for entering a personal identification code of said user; - a step of display, by said access terminal, of said page for entering a personal identification code; subsequently to said step of display of said page for entering a personal identification code: - a step for comparing an authentication code entered by said user with an authentication code pre-recorded within said server; and when said authentication code entered by the user corresponds to said authentication code pre-recorded in said server: - a step of comparison of a current location of said authentication terminal (TAuth) with at least one pre-authorized location of said authentication terminal; and - when the current location of said authentication terminal (TAuth) corresponds to a pre-authorized location, a step for issuing said first assertion of authentication to said access terminal. - a step of dissemination, by the access terminal (TAcc), of a first piece of authentication data; - a step of obtaining by an authentication terminal (TAuth), of said first piece of authentication data; - a step of connection, by said authentication terminal (TAuth), to the server (SrvCMS) at a resource-location address (@LR) derived from said first piece of authentication data; - a step of obtaining, by the server (SrvCMS), of at least one piece of identification data (AuthD) for identifying said authentication terminal (TAuth); and - when said at least one piece of identification data (AuthD) for identifying said authentication terminal (TAuth) corresponds to piece of data pre-recorded (PrDAuth) in said server (SrvCMS): - a step of transmission, to said access terminal, of a piece of data representing a page for entering a personal identification code of said user; - a step of display, by said access terminal, of said page for entering a personal identification code; subsequently to said step of display of said page for entering a personal identification code: - a step for comparing an authentication code entered by said user with an authentication code pre-recorded within said server; and when said authentication code entered by the user corresponds to said authentication code pre-recorded in said server: - a step of comparison of a current location of said authentication terminal (TAuth) with at least one pre-authorized location of said authentication terminal; and - when the current location of said authentication terminal (TAuth) corresponds to a pre-authorized location, a step for issuing said first assertion of authentication to said access terminal. - a step for comparing an authentication code entered by said user with an authentication code pre-recorded within said server; and when said authentication code entered by the user corresponds to said authentication code pre-recorded in said server: - a step of comparison of a current location of said authentication terminal (TAuth) with at least one pre-authorized location of said authentication terminal; and - when the current location of said authentication terminal (TAuth) corresponds to a pre-authorized location, a step for issuing said first assertion of authentication to said access terminal. - a step of comparison of a current location of said authentication terminal (TAuth) with at least one pre-authorized location of said authentication terminal; and - when the current location of said authentication terminal (TAuth) corresponds to a pre-authorized location, a step for issuing said first assertion of authentication to said access terminal.