Methods for Design of Balanced Boolean Functions Satisfying Strict Avalanche Criterion (SAC)

In this paper two methods of designing Balanced Boolean functions for cryptographical transformations are presented. The first of them is based on using orthogonal nonlinear components. The second method realizes a combinatorial approach. Both methods provide high nonlinearity for the obtained functions and both of them operating with Algebraic Normal Form. The advantage of the first method is the simplicity and the technological realization and of the second the significant greatest number of the generated functions compared to the known methods. Key-Words: Boolean functions, balanced functions, SAC-functions