Abstract:
The method for authentication and electronic signature is of the private-key, challenge and response type between a user requesting an authorisation (for a specific transaction, or for access to particular resources), via, for example, a smart card (1) and a controller -check terminal (2)-supplying the authorisation. To increase security of the authorisation or authentication operations, the smart card (1) comprises a chaotic generator (23) generating user's acknowledgement code, which is compared with a comparison code generated by the check terminal (2) using a chaotic generator (30) which is the same.
Abstract:
In order to protect the contents of an electronic document through an encryption system based on an initial confusing step in a scrambler and a subsequent diffusion step in a chaotic processor, both steps being of a chaotic type, initially (51) encryption keys (c j ) and an initial chaotic value (X 0 ) are acquired; input character strings (IN) are acquired (53); diffused character strings (s(t)) are calculated (54) using the input character strings, the encryption keys (C j ), and previous diffused character strings (s(t-j)). After a certain number of iterations, sets of diffused character strings (S j ) are added (63) to subsequent chaotic values (X) generated by a chaotic processor (61) to obtain encrypted words (X CR ). Decryption is obtained through two successive operations, wherein the encrypted words are added to chaotic values identical to the encryption values (X) and subtracted from previously decrypted words using an unscrambler element having a structure similar to that of the scrambler and using identical encryption keys.
Abstract:
The invention relates to an integrated cellular network structure, being programmable to solve partial derivative differential equations in order to control a phenomenon of diffusion or a propagation of electric drive pulses for robot actuators. Advantageously, such structure comprises analog and digital portions interconnected with each other; the analog portion includes a matrix array (6) of analog cells (2) arranged to receive data from an I/O interface (7), and the digital portion includes first and second memory arrays (8,9) for storing a desired configuration and the initial state of such analog matrix array (6), respectively.
Abstract:
The invention concerns a robust communication system (1) for transmissions through a noisy environment, which comprises a cascade of a discrete signal source (2), a chaotic modulator (3) for the signal, a noisy transmission channel (4), and an incoherent discriminator or receiver (5). Advantageously in a preferred embodiment, the incoherent discriminator (5) comprises a high-pass filter (6) effective to remove the lowest frequency harmonics of the received signal, a rectifier (7) providing the absolute value of the wave, a low-pass filter (8) carrying out a mean of the rectified wave, and a comparator (9) placed after the low-pass filter.
Abstract:
The invention concerns a new method of controlling the movements of a multi-actuator electromechanical system which has a matrix of locally interconnected analog cells associated therewith. Each cell represents a hardware implementation of a model of fuzzy inference rules. The model is constructed as a fuzzy circuit architecture which is implemented, preferably, in the form of an integrated circuit with VLSI CMOS technology which generates and controls the reaction diffusion mechanism typical of auto-waves by means of a fuzzy neural network. This fuzzy neural network defines the functional relationships which can duplicate simultaneous reaction diffusion equations, and the duplication of such simultaneous equations is provided by two sets of fuzzy rules processing, in a linguistic manner, the state variables of the cell plurality and imposing on each cell a dynamics of the oscillatory type wherein two dynamic processes having different kynetic characteristics coexist.