The kth-Order Nonhomomorphicity of S-Boxes

The nonhomomorphicity of S-boxes

In this paper we introduce the concept of kth order nonho momorphicity of mappings or S boxes as an alternative indicator that forecasts nonlinearity characteristics of an S box where k is even Main results of this paper include we show that nonhomomorphicity especially the th order nonhomomorphicity can be precisely expressed by using other important nonlinear indicators of an S box we estab l...

The Nonhomomorphicity of Boolean Functions

We introduce the notion of nonhomomorphicity as an al ternative criterion that forecasts nonlinear characteristics of a Boolean function Although both nonhomomorphicity and nonlinearity re ect a di erence between a Boolean function and all the a ne functions they are measured from di erent perspectives We are interested in nonhomo morphicity due to several reasons that include unlike other crit...

On the Distribution and Moments of Record Values in Increasing Populations

Consider a sequence of n independent observations from a population of increasing size αi, i = 1,2,... and an absolutely continuous initial distribution function. The distribution of the kth record value is represented as a countable mixture, with mixing the distribution of the kth record time and mixed the distribution of the nth order statistic. Precisely, the distribution function and (pow...

The KTH Visit in Semi-Markov Processes

Hardware Implementation of Dynamic S-BOX to Use in AES Cryptosystem

One of the major cipher symmetric algorithms is AES. Its main feature is to use S-BOX step, which is the only non-linear part of this standard possessing fixed structure. During the previous studies, it was shown that AES standard security was increased by changing the design concepts of S-BOX and production of dynamic S-BOX. In this paper, a change of AES standard security is studied by produc...