Cryptanalysing the Shrinking Generator

The (a, b)-Shrinking Generator

A new construction of a pseudorandom generator based on a simple combination of two LFSRs is introduced. This construction allows users to generate a large family of sequences using the same initial states and the same characteristic feedback polynomials of the two combined LFSRs. The construction is related to the so-called shrinking generator that is a special case of this construction. The c...

Correlation Analysis of the Shrinking Generator

The shrinking generator is a well-known keystream generator composed of two linear feedback shift registers, LFSR1 and LFSR2, where LFSR1 is clock-controlled according to regularly clocked LFSR2. A probabilistic analysis of the shrinking generator which shows that this generator can be vulnerable to a specific fast correlation attack is conducted. The first stage of the attack is based on a rec...

Improved Cryptanalysis of the Self-Shrinking Generator

An Improved Attack on the Shrinking Generator

This work proposes a known-plaintext attack on the Shrinking Generator through its characterization by means of Cellular Automata. It is based on the computation of the characteristic polynomials of sub-automata and on the generation of the Galois field associated to one of the Linear Feedback Shift Registers components of the generator. The proposed algorithm allows predicting a large number o...

Algebraic Analysis of Shrinking Generator

Algebraic attack is a recently proposed method to analyze the security strength of stream ciphers. This paper provides an comprehensive analysis of the security strength of shrinking generator against the algebraic attack. In our analysis, it will be shown that if the generator is not implemented carefully then it would be highly vulnerable against the algebraic attack. Mathematics Subject Clas...