VLSI Architectures for the Generation of Quasi-chaotic Behavior

In modern communication systems, the advantages of wideband modulation can be coupled with the increasing demand of information confidentiality by using chaotic carriers. In this regard, the use of discrete-time nonlinear circuits based on residue number system (RNS) arithmetic is presented in the paper. For instance, two possible alternatives are considered: the former based on N-order nonlinear IIR filters and primitive polynomials; the latter based on a cascade of first order IIR filters having poles coincident with primitive elements of a suitable Galois field. Such systems will be proved to be very effective in terms of VLSI implementation, since they favorably compare with respect to other secure communication approaches proposed in the technical literature. In particular, very interesting results are obtained in those critical applications where data symbols to be transmitted are characterized by a large number of bits.