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 invention concerns a method enabling a smart card and a terminal whereto it is connected to authenticate each other. The invention is characterized in that at the end of each transaction the terminal calculates, from data representing the card at said transaction end, a secret code CSC2 which is recorded in a zone ZCSC with unprotected access in the card memory and an authentication certificate CA2 which is recorded in a zone ZCA with protected access of the memory by presenting a secret code CSC2. At the next transaction, the terminal calculates, by means of data contained in the card, a secret code and an authentication certificate which are compared to those previously recorded to perform authentication. The invention is applicable to smart cards.

Abstract: In order to render a chip gratuity counter more flexible, the invention consists in recording in the chip card memory a file architecture to facilitate the management of its counters. Said architecture is characterized in that a counter unit file, wherein are located the counters relative to an application, is associated with rules which are applicable thereto. Thus, the simple designation of a counter unit implies the implementation or rules applicable to the counters on the counter unit. The implementation is internal to the chip card and does not require any exchange with the reader. The chip memory further comprises the rules file, the conditions file and the computing file the interaction of which provides greater flexibility of use.

Abstract: A memory card fitted with contacts contains a memory and its access circuits. The memory access circuits are modified to allow recording or reading the memory via electric signals supplied by a terminal according to an asynchronous-type communication protocol with integrity check of the codes transmitted. The signals received on the contacts are analysed by an analysis circuit, then switched to address and data registers by a switch circuit. The analysis circuit and a control circuit transmit messages and codes to the terminal via a transmission circuit.