METHOD FOR AUTHENTICATING A SECURE ELEMENT AT THE LEVEL OF AN AUTHENTICATION SERVER, CORRESPONDING SECURE ELEMENT AND AUTHENTICATION SERVER

摘要

The invention concerns a method for authenticating a secure element (10) at the level of an authentication server (12), the secure element (10) being able to cooperate with a telecommunication terminal, the method comprising: Generating at the secure element (10) a first message comprising a partial IMSI of the secure element (10) or a partial IMSI of an IMSI based user identity that is in the form of a NAI of the secure element, called MSI N_part1, the first message also comprising the MCC and MNC codes of the IMSI or of the IMSI based user identity that is in the form of a NAI of the secure element 10, the MSIN_part1 comprising some of the most significant digits of the MSIN; Generating at the secure element (10) a second message containing a second part, called MSIN_part2, of the MSIN of the secure element (10) and the current sequence number, the second message being encrypted by the key Ki of the secure element (10) in order to provide a token X, the MSIN_part2 comprising some of the less significant digits of the MSIN; Transmitting the first message and the token X to the authentication server (12); At the authentication server (12), creating a list of the candidate secure elements for which the MSIN_part1 corresponds and, for each of the candidate secure elements of the list, decrypting the token X with the key Ki of each of the candidate secure elements of the list, in order to generate a decrypted IMSI comprising the MCC, MNC and MSIN_part1 of the first message and decrypted MSIN_part2 of the token X or a decrypted IMSI based user identity that is in the form of a NAI comprising the MCC, MNC and MSIN_part1 of the first message and the decrypted MSIN_part2 of the token X; Checking at the authentication server (12), for each candidate secure element of the list, which candidate IMSI or candidate IMSI based user identity that is in the form of a NAI : a corresponds to the decrypted IMSI of the decrypted token X; and b has an associated sequence number in a valid range of the decrypted sequence number; At the authentication server (12), generating an authentication vector by using the key Ki of the candidate secure element associated to the IMSI or IMSI based user identity that is in the form of a NAI that matches the decrypted MSIN_part2 of the decrypted token X and the candidate secure element has sequence number in a valid range of the decrypted sequence number in order to launch a challenge response process between the secure element (10) and the authentication server (12).