A study of Algebraic Attack and proposed developed clock control stream cipher

Abstract

Stream cipher is one of the efficient cryptographic primitives to provide confidentiality of electronically transmitted data. Where it is widely used in practice (e.g., in mobile phones, internet ). Researches are interested with different types of attacking on stream ciphers. This paper provide classification for types of attacks on stream cipher and concentrate on the algebraic attack, since it represent the most important among them. Also the paper presents proposed developed clock control keystream generator based on combiner, that has an increase in the complexity of the structure. The Algebraic cryptanalysis was applied for comparing the resistant of proposed generator with LILI keystream generator.