Abstract:
A method for generating a random number sequence whose randomness properties are determined a priori , comprises the steps of defining a parametric map; calculating, in function of parameters of the map, the entropy and the Lyapunov exponent of random number sequences obtainable using the parametric map; identifying at least a set of values of parameters for which the entropy and the Lyapunov exponent are positive numbers the map has no attracting point; assigning a pre-established value as a first feedback value and carrying out cyclically the following steps for generating a random number sequence:
(i) determining said parameters inside the set as the numerical values of respective physical quantities; (ii) outputting a random number, according to said map with the parameters and the assigned feedback value; (iii) assigning as new feedback value said output random number.
A circuit, preferably realized using a switched current technique, implements the method of the invention for generating a random bit sequence.
Abstract:
A PET decoder for ATM network has a modular architecture composed of a processing unit ( PU ) having RO M and SRAM memory means and a processing pipeline ( build _ A , LU _ dec , find _ Y , find _ X ) for constructing from a block of m data of a certain number of bits, a square matrix A based on a vector D of relative points over the Galois field (GF[p]), decomposing by triangular factorization the square matrix A and solving the subsystem of equations by simple substitution, and a control unit ( CU ) interfacing with the ATM network, a programmable parallel processor, a random access memory ( RAM ) and said processing unit ( PU ).