Security of Sponge structures

Sponge structure is a structure widely used in the design of cryptographic algorithms that reduces the design of the algorithms to the design of a permutation or pseudo-random function. The development of sponge-based algorithms and the selection of designs based on this structure in SHA3 and CAESAR competitions increase the need to examine its security against various types of attacks. In the previous article, we defined and examined the features of this structure, and in this article, with the focus on the security of sponge structures, we study general analysis methods on this structure and examine their complexities. Considering the complexities introduced for the general attacks, it is necessary to achieve a certain level of security, and therefore this article, both in terms of design and cryptanalysis of sponge-based algorithms plays important role. It is suggested that the article "Sponge structure; introduction and applications" published in this journal be reviewed before reading this article.