Abstract: The invention relates to an asymmetric cryptographic communication process which establishes a correspondence between a first value (x) represented by n elements (x.sub.1, . . . , x.sub.n) of a ring (A) and a second value (y) represented by m elements (y.sub.1, . . . , y.sub.m) of this ring, n and m being integers greater than or equal to 2. The said correspondence is defined by multi variable public polynomials (P.sub.i) of A.sup.n+m+k ->A, with a low total degree, such that there are equations of the type P.sub.i (x.sub.1, . . . , x.sub.n ; y.sub.1, . . . , y.sub.m ; z.sub.1, . . . , z.sub.k)=0, where(z.sub.1, . . . , z.sub.k) are possible intermediate variables and k is an integer. At least the majority of the polynomials (P.sub.i) do not have the form T.sub.i (y.sub.1, . . . , y.sub.m)=S.sub.i (x.sub.1, . . . , x.sub.n), where the S.sub.i s would be polynomials with a total degree of 2 and the T.sub.i s would be polynomials with a total degree of 1.

Abstract: A coupler for managing communication between a portable data medium and a data exchange device. The coupler includes bistable control circuitry (25) input-activated by at least two control signals (DTR, RTS) delivered by the data exchange device in one of two first and second predetermined input sequences, and arranged to output at least one power supply signal (VCC) and a data medium reset signal (RST) in a predetermined output sequence, such that the portable data medium is activated only when one specific input sequence of the two input sequences is received.

Abstract: A method and an apparatus for authenticating a data carrier enables a transaction or access to a service or a location, and the corresponding carrier. The carrier (1) has a specific number (Ns) and an authentication value calculated from the specific number and from information (I) that defines the rights attaching to the carrier by means of an asymmetrical algorithm (F) and a secret key (Ks). Two types of authentication are provided. One is current, in a mode disconnected from the authorizing organization. The other is periodic, in a connected mode. In the disconnected mode, an algorithm (G) correlated with the asymmetrical algorithm (F) and using a public key (Kp) is applied to the authentication value (VA), read from the carrier, in order to verify that the authentication value (VA) is compatible with the specific number (Ns) and the information (I), and that the transaction or service requested is compatible with the information (I).

Abstract: With confidential information being composed of authenticating signs which belong to a first series, a second series of signs or designating symbols is defined, the first and second series of signs are displayed in a relatively random position, and this placement in correspondence is used to enter the confidential information in such a way that a third party who observes the entry operations cannot determine the confidential information. The invention also relates to the terminal associated with this process.

Abstract: The invention consists of writing at least one piece of information ?I! and an image ?I'! thereof into the accessible memory zone Ac of a portable object (1). This image ?I'! is obtained by implementing a program of encipherment of the information ?I!. This program takes into account at least the one piece of information ?I!, a first datum ?Ks! that is external to the portable object and furnished to encipherment circuits (21) under the control of the person writing the information, and a second datum ?Sid! that is diversified for each portable object (1). Later certification consists of verifying that an image ?I'! has been obtained with the aid of the first and second data, so as to deduce from this that the associated information ?I! is original.

Abstract: A data processing system is provided which includes at least one processing unit and at least one nonvolatile memory which is electrically erasable and reprogrammable at least under the partial control of the processing unit, with the system further including a reinitialization request signal detector which is operatively connected to a programming voltage inhibitor which is capable of inhibiting or preventing the application of at least one signal (V.sub.pp, WE, EE) to the nonvolatile memory, the signal being necessary for the programming of the nonvolatile memory, the reinitialization request signal detector operating to control the inhibitor such that the signal is inhibited from being applied to the nonvolatile memory at least when the reinitialization request signal is detected at a level sufficient to activate reinitialization.

Abstract: This invention concerns a key protection device for smart cards and is characterized by the fact that:each input user key is coded using a random key and stored;protection data that corresponds to each coded user key's dependant data is generated and associated to each coded user key;a detection device is installed on the card that allows the user to verify the stored user key's integrity by comparing the protection data to verification data that is generated using the card's stored user key; andan interlock device that allows the user to block any further calculation using the stored key in the event that the verification data is not identical to the protection data.

Abstract: A process for authentication by an offline terminal (1) of a portable object (2) including a processing circuit (4) able to deliver a secondary value (Rx) which the function of a primary value (Qi) transmitted by the terminal. An authentication table (5) is placed in the terminal which associates a series of primary values (Qi) and a series of control values (Ui), each control value being the transformation by a oneway function of the secondary value (Rx) calculated by the processing circuit of an authentic portable object. At the time of a connection of a portable object with the terminal, one of the primary values (Qi) from the table is transmitted to the portable object, the one-way function is applied to the secondary value (Rx) received from the portable object, and the result obtained is compared with the corresponding control value (Ui) from the table.

Abstract: The invention relates to a method for signature of a primary information processing file (FP), of the type consisting of causing circuits of an information processing device (1, 3, 4) to calculate at least one signature (SG) of the file, by using at least one secret datum (S; Sd) specific to the signer, but unknown to him, memorized in a secret memory zone of a portable electronic object (4), having a memory and processing circuits, which is at the disposal of the signer, and linking the calculated signature to the primary file.

Abstract: The invention relates to a method and apparatus for checking the integrity of a message such as a program and/or data against an original message supposed to correspond to it.By using an algorithm (A) on at least part of the original message, at least one signature (S1, S2, . . . Sm) of this part is calculated and memorized in a memory area (10) of a portable object (1) which also has processing circuits (11) able to implement algorithm (A). In order to check the integrity of a message, at least one signature of a message part is calculated by the processing circuits (11) of the portable object by implementing the algorithm (A) and is compared to an original message signature supposed to correspond, and memorized in memory area (10).

Abstract: The present invention relates to a system including a terminal connected by a transmission line to a central processing unit, the terminal including a memory divided into a program memory and a working memory of the RAM type, the program memory in turn including a volatile memory, a safeguarded memory of the EEPROM type or RAM type with batteries, and a resident memory of the ROM or PROM type, characterized in that each of the memories comprising the program memory is divided into a noncertified zone, the terminal including an interpreter program for interpreting between a program written in a high-level universal compact language and the language specific to the microprocessor of the terminal, this interpreter program being capable of access to each of the memory divisions, and a remote loading monitoring program including at least one instruction CHSB, the command word of which is stored in one of the registers and expresses the remote loading possibilities of the various zones.

Abstract: A method for generating a random number in a system utilizing portable objects, such as cards with electronic memories and data processing circuits, wherein the data processing circuits (TC) of the portable object are operable to generate a random number required for data processing, when the portable object is connected to a processing apparatus of the system. A calculation program recorded in the circuits of the portable object is executed taking into account parameters memorized in the memory (MC) of the object.

Abstract: The invention relates to a portable user controlled pointing peripheral device enabling connection of a memory and/or microcomputer module (44) to a processing machine, without requiring a specific connector and/or interface circuit, while preserving the portable nature of such a module. The main characteristic of the invention resides in the fact that the device additionally constitutes a pointing peripheral (47, 48, 49), such as a "mouse", and the electronic circuits of the device are arranged to use conductors (RXD, TXD, RTS, DTR) which are shared between the machine and the device in order to permit the use of the pointing functions and the use of the functions of the module.

Abstract: In a data processing system using portable objects (1) such as cards incorporating memory chips (11, 12, 13, 14, 15) and a processing circuit (10), where a first memory zone (11) is electrically erasable and writable at the request of the processing circuits in the object, random numbers are generated taking into account a first parameter taken from the first zone (11) and at least one second parameter written in a second, nonvolatile zone (12) of the object, the content of this second zone being modified each time the first zone is erased such that the combination of parameters is never identical following the various erase operations on the first zone.

Abstract: An electronic microcircuit card and method for its manufacture are disclosed. Contacts 12 that are accessible through an opening 26 of the card 10 are raised by a boss 27 formed under the contacts in such a manner that they come approximately to the level of the outer face 22a of the card. The invention applies particularly to credit cards, the thickness of which meets the standard for credit cards as established by the International Standards Organization (ISO).

Abstract: A flexible printed circuit having contacts and associated leads which are connected to the contacts. The contacts are disposed at a first zone and the leads are for connection from this zone to a second zone of the circuit which is at a distance from the first zone. The leads run from the respective contacts substantially perpendicular to the axis of the printed circuit which connects the two zones. The leads in turn form bends or loops in relation to the axis, up to the second zone.

Abstract: The invention relates to a method for authenticating an external authorizing datum by a portable object, such as a memory card.The authorizing datum (C1) entered into an apparatus (2) is enciphered with a predetermined datum (E) to yield a message (M) which is transmitted to a portable object (1). The object (1) deciphers the message (M), taking into account a reference authorizing datum (C1), in order to retrieve a datum (E'), which must be coherent with the datum (E).The invention applies in particular to the recognition of the carrier code of the owner of a credit card.

Abstract: The subject of the invention is a method for certifying the authenticity of a datum exchanged between two devices connected locally or at long distance by a transmission line.The transmitting device (2) fashions an enciphered message (M) on the basis of a parameter (X) at least one field (X1) of which must satisfy a predetermined condition and one field (X3) corresponds to the datum (d) to be transmitted. The receiving device (1) deciphers the message (M) in order to find a parameter (X') the field (X'1) of which must satisfy the same condition as the field (X1) for which the field (X'3) corresponds to the datum (d) transmitted.The invention is applicable in particular to credit cards.

Abstract: A method and apparatus for certifying services obtained with the aid of a portable carrier such as a memory card. A portable carrier (2) such as a credit card is adapted to be connected to an apparatus (1) that calculates a visual record or certificate (C), composed of a result (R) and parameters (PI, PE) necessary for calculating the result. This result is calculated by processing circuits (T2) in the card (2) under the control of a program (P2) recorded in its memory (M2) and of a secret key (S). The result emitted after a service has been furnished can then be recalculated, to certify that the service has been furnished.

Abstract: The invention relates to a security device (1) prohibiting the execution of at least one function of an electronic data processing unit (2) after a first cutoff of its electric power even in the case of a resumption of supply voltage.This device includes a first means (8) that functions only once in the course of a period beginning at the instant (T.sub.0) of a first connection to voltage by the power supply (3), and finishing prior to the instant (T.sub.2) of a first cutoff of this power supply, and a second means (10) connected to the output of the first means (8) and furnishing an inhibiting signal having a first level that authorizes the function of the unit, from the instant (T.sub.0) of the first connection to voltage until the instant (T.sub.2) of the first cutoff, this inhibiting signal having a second level that prohibits said execution of said function beginning at the instant (T.sub.