1. Using Evolving Algorithms to Cryptanalysis Nonlinear Cryptosystems
- Author
-
Faez Hassan Ali and Riyam Noori Jawad
- Subjects
Discrete mathematics ,Ant Colony Optimization (ACO), Cryptanalysis, Genetic Algorithm (GA), Shrinking Generator, Stream Cipher ,General Computer Science ,General Mathematics ,General Physics and Astronomy ,010103 numerical & computational mathematics ,02 engineering and technology ,General Chemistry ,01 natural sciences ,Agricultural and Biological Sciences (miscellaneous) ,General Biochemistry, Genetics and Molecular Biology ,law.invention ,law ,0202 electrical engineering, electronic engineering, information engineering ,Cryptosystem ,020201 artificial intelligence & image processing ,lcsh:Q ,0101 mathematics ,Hardware_ARITHMETICANDLOGICSTRUCTURES ,Cryptanalysis ,lcsh:Science ,Stream cipher ,Mathematics ,Shrinking generator - Abstract
In this paper, new method have been investigated using evolving algorithms (EA's) to cryptanalysis one of the nonlinear stream cipher cryptosystems which depends on the Linear Feedback Shift Register (LFSR) unit by using cipher text-only attack. Genetic Algorithm (GA) and Ant Colony Optimization (ACO) which are used for attacking one of the nonlinear cryptosystems called "shrinking generator" using different lengths of cipher text and different lengths of combined LFSRs. GA and ACO proved their good performance in finding the initial values of the combined LFSRs. This work can be considered as a warning for a stream cipher designer to avoid the weak points, which may be found in the stream cipher, and may be explored by the cryptanalysts. This work can find the optimal solution for text with minimum lengths of 20 characters and 100 iteration were very enough to find the real initial values of key stream.
- Published
- 2020