Statistical assessment – as a part of security assessment applied to a block cipher

The security provided by the block cipher algorithms is a top modern approached issue within the specific researches. The security assessment of a block algorithm involves the assessing and testing of components, the statistical testing of algorithm and last, but not least, the cryptanalysis. This paper intends to approach a part of this issue by presenting one of the security assessment stages, namely the component analysis, together with the statistical testing of the block cipher. The statistical testing may be considered as a first step in the security assessing of a block algorithm. The statistical testing of randomness of the block cipher represents an essential phase, both, for the research-development process, and for the assessment process applied to the cryptographic primitives, taking into account that the block algorithms are used on a large scale in cryptographic applications. Assessing them, from a cryptographic point of view, is a highly complex task, which cannot be efficiently accomplished by formal methods. This paper presents several statistical methods of carrying out a security assessment on a block algorithm.