Based On Groebner Basis The Algebraic Attack Methods Of Research

Recently,a new technique for cryptanalysis,algebraic attack,received a general concern by cryptographists.In this paper, We will show the main theory of algebraic attacks based on Groebner basis,and discuss the main threats posed to the common cipher systems.The principle of algebraic attacks is to set up a system of multivariate polynomial equations describing internal stages of encryption on any cipher with the input(key) bits as unknowns,and try to resume the keys by solving this system in case it is low degree, overdefined,or sparse.This paper proposed a new method of Groebner Basis Attack which can significantly improve the ability of algebraic attacks,and analyzes the complexity of it.This paper will be divided into five sections focused on this topic.Part I introduces briefly the development of the algebraic attacks and the threat to the common ciphers. Part II introduces the Groebner base theory in detail. Part III shows how to improve the oringin algorithm based in the Groebner base system,and compare the new algorithm with the other similar ones. Part IV uses the new method to attrack the CTC2systems,and analyse the result. Part V discusses the algebraic immunity about the block ciphers.