Abstract: The invention concerns a method for duplicating data contained a smart card memory in the memory of another smart card, which consists in producing for said other card another management code, another secret code. Said other management code is produced on the basis of identification data particular to the first card and also particular to the second card. For the system to operate, identification data concerning the first card are also recorded in the second card.

Abstract: Releasable PCMCIA cards (10) suitable for plugging into the slot (12) of a micro-computer (14). To enable the releasable plug-in card (10) to be used as a smart card reader, it is altered in such a way that it can receive a smart card (22). For this purpose, the releasable card (10) includes a guide system (15) with a shape matching that of a smart card (22) so that the smart card is properly positioned relative to the reader. A micro-computer or PCMCIA card may thus be protected by means of a security smart card.

Abstract: Releasable PCMCIA cards (10) suitable for plugging into the slot (12) of a micro-computer (14) arc disclosed. To enable the releasable plug-in card (10) to be used as a smart card reader, it is altered in such a way that it can receive a smart card (22). For this purpose, the releasable card (10) includes a guide system (15) with a shape matching that of a smart card (22) so that the smart card is properly positioned relative to the reader.

Abstract: A system for loading an applet and its associated use rights into a smart card having other applets with associated use rights with values that change as the application is used is provided that stores, remotely from said smart card, an applet and use rights with a predetermined initial value, associated with the applet, and has a smart card having a processing unit, and a memory unit, the memory unit being connected to the processing unit and storing a second application having use rights. The smart card may be connected to said remote storage means, and the application, having use rights with a predetermined value, may be loaded from said remote storage means into said smart card.

Abstract: A method for updating information elements in a memory which includes a plurality of memory locations. An initial value D0 has been written at a first location E0 of the memory, E0 being determined by an initial value of a string of indicator bits, the initial value being defined by the parity of the rank of a last bit of the string of indicator bits in a programmed state.

Abstract: The method is designed to increase the protection of a microcircuit-based memory card comprising at least one memory coupled to a data-processing element. When said data-processing element receives a command by a data signal external to the card, said method consists in making said data-processing element emit a ratification signal at an instant that is deferred, with respect to the instant at which its emission was prompted by the data signal, by a duration that is randomly variable in time. The disclosed method can be applied to microcircuit-based memory cards.

Abstract: The card has a plastic support bearing, on at least one part of its surface, a layer of recording material and a microcircuit inserted in the plastic support. The card is made tamper-proof by the setting up of an identifier code that is characteristic of the relationship between the microcircuit and the support bearing the recording layer. This code is, firstly, recorded in the memory of the microcircuit and, secondly, detectable by analysis of the support. Any detachment of the support and of the microcircuit in which the related code has been memorized prevents the checking of the two codes by coincidence. The invention can be applied notably to high storage density cards.

Abstract: To avoid differentiation, in manufacture, between the random-access memory cells and read-only memory cells of the same memory array, the memory cells are all made by the same technology. These memory cells employ essentially floating gate transistors. The random-access memory cells are programmed, in a stand way, by injecting or not electronic charges in the floating gates of the transistors. The read-only memory cells are put in a programmed or an unprogrammed state by the selective implantation of impurities or not in the conduction channels of the floating gate transistors of these memory cells. There is an improved concealment of the content, which is designed to remain concealed, of these memory cells, at the same time, the conditions for making prototypes to order are improved.

Abstract: The microcircuit card is such that at least one strain-indicating sensor is placed on the microcircuit, in a known state of strain, and is maintained in this state by a protection layer deposited on the microcircuit for as long as this layer is not affected. The microcircuit has means for measuring an electrical value that is characteristic of the strain, and a logic circuit connected to the measuring means to detect the changes in the condition of strain indicating an intrusion into the card.

Abstract: The use of chip cards, with the level of security of the type associated with chip cards of the type used by banks, is extended to move widespread use by organizing a secure dispatch of blank chip cards to customers wishing to program specific applications therein. The system consists in sending this customer the blank chip card itself and a programming access key to this card, by separate routes. To prevent any additional risks, the access key is itself enciphered and can be deciphered only be a deciphering element in the possession of the customer. The card can then be programmed only if this card is confronted with its deciphering key.

Abstract: A fraud-preventive device for a memory card comprising an EPROM type or similar non-volatile memory designed to receive confidential authorization data as well as the results, wrong or otherwise, of tests on the authorization data, comprises a single simulation cell designed to record the non-erroneous results, this cell consuming the same current as a memory cell, which has never been programmed, of the memory part designed to record the wrong data.