Zohreh K. Pseudorandom sequences generation program-hardware means for increasing the data protection efficiency in computers and networks

Thesis is dedicated to a problem of working out the binary pseudorandom sequences generators which improve the sequences quality characteristics which have an impact on data protection efficiency. The most attention has been concentration on the design techniques of Nonlinear Feedback Shift Register (NFSR) with nonlinear feedback Boolean function, which ensure the repeat cycle 2n for n-bit register. The properties of such function have been studied by the theoretical way. The base conception of the obtaining nonlinear feedback functions which ensure the repeat cycle 2n for n-bit shift register consist of directly uniting of codes cycles – sets n-bits codes which have been created by rotation. The analysis of number of functions which can be designed by proposed method has been worked out. It has been proved that proposed method allowed to increase the number of obtained feedback nonlinear function on one order in compare to known methods.