МОДЕЛИ ХАОТИЧЕСКИХ СИСТЕМ С УПРАВЛЯЕМОЙ СИММЕТРИЕЙ В ПОТОКОВОМ ШИФРОВАНИИ

Abstract

Information safety plays an important role in modern technologies. A stream encryption is one of the common means for information safety support. The sequences with pseudo-random characteristics are often required in the algorithms of stream enciphering. Random systems are recently used as a source of pseudo-random numbers with desired statistical properties. A small length of a sequence period is one of the known problems of the generators of pseudo-random numbers based on chaos realized with a small length of a digit grid. The disturbance of a path or a parameter of random system nonlinearity is one of possible solutions of a short period problem. In this paper there is considered a new approach to the increase of a period length through the change of a symmetry factor in the random model of a memristive circuit. The approach offered is based on switching two values of the symmetry factor in accordance with the output of a shear register with the linear feedback. To confirm the effectiveness of the disturbance circuit described the lengths of a period for the disturbed and original model of the memristive system are estimated. The properties of the output sequences caused by a generator on the basis of the model with controlled symmetry are confirmed by the results of the correlation analysis and NIST statistical testing. 
 The results obtained can be used in cryptographic applications and also at the designing of safe communication systems.