METHOD FOR SECURING AN AUTHENTICATION AND KEY AGREEMENT PROTOCOL

The present invention concerns a method for securing an authentication and key agreement (AKA) procedure used in a third-generation mobile system, comprising the following steps: a. Sending the standard Authentication Vectors (AV) from the Secure Server (SS) to an Authentication Server (AS); b. Modifying in the Authentication Server (AS) the MAC and/or any other parameter not used as input of the computation of cryptographic key material, sent by the Secure Server (SE) to the AS (Authentication Server); c. Sending from the Authentication Server (AS) to the Secure Element (SE), through a mobile client said modified data; d. Detecting, in the Secure Element (SE) the modification of the said data; e. Sending, in the Secure Element (SE) the standard AKA output except for the key material, which remains unavailable to the mobile user.