Abstract: The invention relates to a secure data processing method comprising the steps of generating (E204; E304) a first random value (A1); executing (E206; E306) a first cryptographic algorithm (FK) using the first random value (A1); generating (E208; E308) a second random value (A2); executing (E210; E310) a second cryptographic algorithm (FK; GK) using the second random value (A2); and generating a result (V) to verify that the first algorithm (FK) was properly executed.

Abstract: The invention concerns a secure electronic entity (11) containing a time measuring unit (18) and comprising a unit (21) for certifying an information concerning a date or a time interval, the certifying unit (21) receiving from the time measuring unit (18) data concerning the date or the time interval and producing certification data of the information concerning a date or a time interval addressed to and external entity. The invention is applicable in particular to microcircuit cards.

Abstract: A method for protecting an electronic entity with encrypted access, against DFA (Differential Fault Analysis) attacks which includes: storing the result of a selected step (Rm, Kn) of an iterative process forming part of the cryptographic algorithm and in performing once more at least part of the steps of the iterative process up to a new computation of a result corresponding to the one which has been stored, comparing the two results and denying distribution of an encrypted message (MC) if they are different.

Abstract: An exchange of information between a communication entity e.g. a mobile telephone and the operator server upon which it is dependent, in order to carry out authentication operations by exchanging keys and using cryptography algorithms. According to the invention, an algorithm is used, comprising: algorithmic treatments (35A, 35B) using, as input data, all or part of a random number (FAND) and operating keys (KA, KA2-Kd) derived from two keys (K; Kd), and a combined treatment using data derived from said 10 algorithmic treatments in order to provide results (SRES, K.) enabling the linkage.

Abstract: The process is done by means of a transactional identifier server storing a description of service offers taken out by the user from service providers, in a memory for each user. The transactional identifier server comprises a management module used to associate an opaque transactional identifier with a user and a service.

Abstract: To broadcast a set of multimedia contents to mobile terminals located in a geographical zone, a broadcasting server addresses them through a short broadcast message. A geographical zone is defined as a set of cells of a mobile telephony network. The short message is received by all the mobile terminals present in these cells. The reception of this short message prompts the connection of this terminal to the broadcasting server for the retrieval of a set of multimedia contents associated with the short message. The retrieval is done in either WAP/GPRS mode or voice mode.