Em Microelectronic-marin Sa

Julian Guilloux

Stéphanie Salgado

Tomas Novak

A method of authenticating a transponder communicating with a server, including: calculating a one-time password in the transponder with a dedicated algorithm, on the basis of the state of a counter and a physical quantity, such as a transmission delay determined in the transponder during reading by a reading device; transmitting the password to the server by the reading device, which determines a transmission delay of the transponder, and transmitting to the server, in addition to the password, the information about the transmission delay determined in the reading device; decrypting by the dedicated algorithm the password, and checking if the decrypted transmission delay of the received password corresponds to the transmission delay determined by the reading device within a determined temporal margin, and if the state of the counter is different from a received previous state of the counter so as to authenticate the transponder.

Method of securely authenticating a transponder in communication with a server

A method of authenticating a transponder in communication with a server. The method includes the steps of defining a word in the transponder with a previous state of a counter of the transponder, incremented by a random number generated in the transponder, calculating a one-time password in the transponder with the aid of an HOTP algorithm and of a secret key on the basis of the word, transmitting the word and the one-time password to the server, calculating another one-time password in the server with the word received from the transponder by the HOTP algorithm and with one and the same secret key, and checking whether the passwords are identical so as to authenticate the transponder and authorize access to a site determined by the server.

Growing community of inventors

Colombier, Switzerland

Julian Guilloux