Patent ID: 6055638
Filing Date: 2000-04-25
Classification: G06F

Abstract:
Secured authentication process for the communication between a least one user terminal (PC/Ui) and a server through a communication network, the terminal being intended, in particular, to read the content of an authentication device dedicated to the user depending on information coming from the server, process comprising steps of:a) creating, in the server and in a pseudo-random manner, a data group peculiar to the user called data-server group, containing specific signs at specific addresses;b) duplicating this data-server group on the authentication device dedicated to the user, then called data-user group;c) transmitting to the user the dedicated authentication device;d) establishing a link between the terminal (PC/Ui) and the server;e) generating, in the server and in a pseudo-random way, addresses of the data-server group making it possible to locate a server code (CS);f) transmitting these addresses in a first server-to-terminal direction;g) reading in the terminal (PC/Ui) a user's code made up of the content of the data-user group at these transmitted addresses;h) transmitting in a second terminal-to-server direction the user's code (CU) which was read;i) comparing the user's code (CU) with the server code (CS); andj) validating the user's authentication if the user's code (CU) is identical to the server code (CS),wherein before step b), it comprises the step which consists in:b1) applicating, in a pseudo-random manner, a shift function (D) to the data-server group, in order to obtain a shifted data group (MD/Ui), according to a shift code (CD) which results from the application of a pseudo-random shift function (D), the code (CD) being proper to each user;the data group duplicated on the authentication device (3) dedicated to the user being the shifted data group (MD/Ui);the dedicated shift code (CD) being separately transmitted from the authentication device (3),and before the operational step g), the process also comprises the step which consists in:g1) entering, in the terminal, the dedicated shift code (CD) in order to apply the shift function corresponding to the addresses transmitted or to the content of these addresses;the user's code (CU) read in the terminal (PC/Ui) being made up of the content of the data-user group corresponding to the addresses transmitted to which a shift function (D) has been applied, according to the dedicated shift code (CD) or to the content of the data-user group to which a shift function (D) has been applied.