Abstract: Pressure regulation in a liquid reservoir such as an ink of a jet printing head, is obtained by transferring a calibrated gas volume through an auxiliary reservoir, said regulation is being applied to installations manufacturing intelligent portable objects and more particularly to graphic customization stations.

Abstract: The invention relates to a device for securing access to a piece of equipment (EQP), comprising an authentication medium (CRD) which uses a reference datum and control means (CTRL) which can be used to verify the consistency between the reference datum and a biometric signature (SGN) obtained from a party requesting access. According to the invention, the reference datum comprises an encrypted version (CRYPT_SGN02) of an authentic biometric signature (SGN02) attributed to the party requesting access, and the aforementioned data consistency is verified by comprising (COMPAR) the biometric signature (SGN) obtained from a party requesting access to an authentic biometric signature (SGN02) resulting from decryption of the encrypted version (CRYPT SGN02) of said signature using a secret key (K).

Abstract: The invention concerns a method solving security problems resulting from the addition of a security circuit to a smart card reading terminal by providing said security circuit with means for counting the number of times the security circuit is activated for certain sensitive operations. When the total of said operations reaches a fixed value, the security circuit is prevented from operating until it is re-initialized again. Optionally, the circuit may have to be replaced by another.

Abstract: A device external to a terminal transmits a specific application identifier and an encrypted first key and number to a first chip card in service in the terminal. In the first card, if the decrypted first number satisfies a first condition, the specific application is called up, application data are read, the data are encrypted using the decrypted first key to transmit them to the external device, and the application is made inoperable. Following replacement of the first card by a second card, the external device transmits the identifier and an encrypted second key and number to the second card. In the latter, if the decrypted second number satisfies a second condition, the encrypted data are transmitted to the second card so that the latter calls up the application, decrypts the encrypted data using the decrypted second key and installs said data.

Abstract: A cryptography method for generating probabilistic digital signatures and/or for a key-exchange a protocol and/or for an encryption algorithm is based on the use of a public key algorithm on abnormal binary elliptic curve, such as a Koblitz curve. A point P (x, y) is selected, and pairs (ki, Pi) are stored with Pi being the point corresponding to the scalar multiplication of the point P by ki. A random variable (k) is generated and a point C is calculated that corresponds to the scalar multiplication of P by k. The generation of the random variable (k) and the calculation of the point C are performed simultaneously.

Abstract: A countermeasure method in a first electronic component communicating with a second electronic component uses a secret key K[0] cryptographic algorithm A of size k. The countermeasure implementation employs a systematic and regular evolution of K[i] by a function K[i]=f(k[i?1]), and transmission of i to the second component. A computational shortcut enables the second component to compute K[i] from K[0] without having to generate the i?1 keys K[1] to K[i?1] separating K[0] and K[i].

Abstract: The invention relates to cards with a microprocessor and contacts. The invention lies in the fact that a communication device of the asynchronous type is disposed between the contacts and the microprocessor so as to relieve the microprocessor of the communication tasks and thus allow better use of the central unit of the microprocessor and the associated memories. This device includes an analysis circuit, a circuit for checking the integrity of the series of pulses, a circuit for determining the characters in the series of pulses and pluralities of registers which are connected with the microprocessor.

Abstract: The ability to utilize smart card based Internet applications is facilitated by enhancing the functionality of smart cards dedicated to other applications, to enable them to connect to and interoperate with Internet application servers. The functionality of subscriber identification module (SIM) card is enhanced to incorporate the information necessary to interact with an Internet-based application service provider. The user can also employ a conventional smart card to access an Internet application from a personal computer or other terminal equipped with a conventional smart card reader, and use the SIM card to interact with application when access to a conventional smart card reader is not available. The application server recognizes the distinction between access with the two different types of cards, and ensures that both cards are synchronized with one another.

Abstract: An adapter for a portable integrated circuit device of the chip card variety has a reduced format in comparison with the standard mini-card format. The device with a reduced format includes a body on which a microcircuit defining contact pads is disposed. A support which has a standard mini-card format is provided with a cavity having the dimensions of the device with a reduced format. The device is detachably fixed in the cavity. The cavity is located in the support in such a way that the location of the contact pads of the microcircuit of the device with a reduced format coincides with the standardization location of the contact pads of a microcircuit having a standard format mini-card.

Abstract: The present invention concerns an anti-SPA modular exponentiation algorithm in an electronic component using a public key ciphering algorithm. A pair of registers and an indicator are used to provide symmetrical processing of bits in the algorithm, so that the values of individual bits cannot be determined from power consumption.

Abstract: The invention concerns a method for differentiating between data and instructions thereby providing against certain attacks in a data processing device such as a smart card, whereby a generator associates a random number with an applicative component of a downloaded application, and a transformer in a virtual machine applies each of the instruction words in the component and the associated random number to a transformation function so as to store the transformed instruction words when downloading the component. A second transformer applies each of the transformed words of part of the component and the associated random number to the reciprocal function of the transformation function so as to retrieve the instruction words constituting the component part, to execute the same.

Abstract: In a method for monitoring the flow of execution of a series of instructions of a computer program, a sequence of instructions are transmitted to the processor to execute the monitored program. These instructions are analyzed, and the result of the analysis are verified by referring to reference data recorded with the program. The reference data can include a value predetermined in such a way as to correspond to the result of the analysis produced during the monitoring process only if all the instructions have been actually analyzed during the program flow. The invention also concerns a device for monitoring the program execution, a program device, and a programming device operating according to the monitoring principles.

Abstract: Elliptical curve based cryptographic algorithms are public key algorithms offering a shorter calculation time and smaller key sizes in comparison with RSA. In a smart card type environment, these algorithms are vulnerable to differential power analysis (DPA) attacks. The disclosed invention provides a countermeasure procedure enabling positive action to be taken against DPA-type attacks. The countermeasure does not reduce performance and is easy to use in a smartcard type component.

Abstract: A random prime number is generated within a predetermined interval by precalculating and storing a single value that functions as a universal parameter for generating prime numbers of any desired size. The value, ?, is chosen as a product of k prime numbers. A number a is also chosen such that is co-prime with ?. Once the values for ? and a have been determined they can be stored and used for all subsequent iterations of the prime number generating algorithm. To generate a prime number, a random number x is chosen with uniform distribution, and a candidate prime number within the predetermined interval is calculated on the basis of the random number. This candidate is tested for primality, and returned as the result if it is prime. If the candidate is not prime, the random number x is multiplied by a, and used to generate a new candidate. This procedure is repeated, until the candidate is prime. Since a single value, namely ?, needs to be precalculated, economies of storage are achieved.

Abstract: Two methods for random number generation are modified to make them more resistant to attacks by current measurements. The methods are particularly designed to be implemented in electronic devices such as smart cards, PCMCIA, badges, contactless cards or any other portable device. The DES algorithm is encrypted using a key K having a value D representing date information, to generate an integer variable I. For j ranging from 1 to m, the following steps are carried out: substituting s with s XOR I; introducing in the integer variable y the result of the encryption of s with the DES algorithm using the key K; introducing in xj the result of y or s; substituting s with y XOR I; and introducing in s the result of the encryption of s with the DES algorithm using the key K. The sequence (x1, x2, xm) is then restored in the output.

Abstract: A countermeasure method in an electronic component which uses an RSA-type public key cryptographic algorithm. A first countermeasure method uses a random calculation for each new execution of the decryption algorithm with CRT. The calculations are made modulo p*r and q*t, r and t being random numbers. A second countermeasure makes the recombination random using the CRT theorem.

Abstract: A random number that is co-prime with a set of prime numbers is generated, without having to calculate the greatest common denominator of the numbers. The value of 1?x?(mod ?), where x is a randomly generated value and ? is the Carmichael function, is tested to determine whether it is non-zero. If it equals zero, x is chosen as the random number of interest. Otherwise the value for x is updated, and the procedure is repeated. Due to the minimal amount of computation resources required to select x, the process is particularly well suited for generating cryptographic keys in portable electronic devices, such as smart cards.

Abstract: A method for the secure application of a cryptographic algorithm of the RSA type in an electronic component obtains the value of a public exponent e from a given set of probable values, without a priori knowledge of that value. Having determined the value for the public exponent e, the application of countermeasures using the value of e, to block error attacks and side channel attacks, particularly of the DPA and SPA type, are carried out on the application of a private operation of the cryptographic algorithm.

Abstract: The invention relates to a method for detection of saturation of files or applications in a mobile communication device (10) connected to a remote control center (12) and a message server SMS-SC (14), characterised in comprising the following principal steps: (a) detection of a data file (38) or data application contained in a SIM card (16), the free space of which is below a certain threshold and (b) generation of an alarm signal after said threshold is reached.

Abstract: The invention concerns a chip card receiving fields of compressed data encapsulated in frames including an indication of the expected length of decompressed data and a length of compressed data. The frames are received in a storage unit and the processor of the card decompresses each data field according to a decompression algorithm over a length based on the indication of the expected length and writes the decompressed data in another buffer storage unit. Several algorithms and optionally several decompression models are installed in the card storage unit, and a couple thereof is selected by the number read in the heading of each frame received.