динамический хаос

Cryptography from the Physicist's Point of View

The results of treating of crypto algorithms such as DES (USA) and GOST 28147-89 (Russia) with the help of nonlinear dynamics methods are presented. Point maps which are generated by the blocks of substitutions (S-blocks) are investigated. The phenomenon of return is demonstrated. The ergodicity of these maps are treated. An estimation of quality of S-block could be made by maps of first return. The results of statistical treating of S-biocks are presented.

Dynamical Chaos In Quantum Systems

Authors: Lazerson A. G., Boykov A. A.

Complex dynamics of a quantum periodically driven square well is considered. It is shown that analysis of its ensemble average energy time series provides an identification of its dynamics to be either regular or chaotic. It has been found that enhancement of the driving force causes the energy spectrum to look like a spectrum of some random process, which may be identified as the signature of chaos in a quantum system.