• Title/Summary/Keyword: shrunken-interleaved sequence

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Analysis of Shrunken-Interleaved Sequence Based on Cellular Automata (셀룰라 오토마타 기반의 수축-삽입 수열의 분석)

  • Choi, Un-Sook;Cho, Sung-Jin
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.14 no.10
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    • pp.2283-2291
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    • 2010
  • The shrinking generator which is one of clock-controlled generator is a very simple generator with good cryptographic properties. A nonlinear sequence generator based on two 90/150 maximum length cellular automata can generate pseudorandom sequences at each cell of cellular automata whose characteristic polynomials are same. The nonlinear sequence generated by cellular automata has a larger period and a higher linear complexity than shrunken sequence generated by LFSRs. In this paper we analyze shrunken-interleaved sequence based on 90/150 maximum length cellular automata. We show that the sequence generated by nonlinear sequence generator based on cellular automata belongs to the class of interleaved sequence. And we give an effective algorithm for reconstructing unknown bits of output sequence based on intercepted keystream bits.

Attack using Phase Shifts of Shrunken Sequence (수축수열의 위상이동차 공격법)

  • Choi, Un-Sook;Cho, Sung-Jin;Hwang, Yoon-Hee;Kim, Han-Doo
    • The Journal of the Korea institute of electronic communication sciences
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    • v.6 no.1
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    • pp.97-104
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    • 2011
  • Pseudo-random sequences with high linear complexity and low correlation function values are widely used in communication and cryptology. In this paper, we study the properties of interleaved sequences generated by shrinking generator. And we give a method for obtaining the shrunken sequence from a partial description of the shrunken sequence by using the phase shifting of PN sequences generated by shrinking generator.

Synthesis of 90/102(170)/150 linear CA using 90/150 linear CA (90/150 선형 CA를 이용한 90/102(170)/150 선형 CA 합성)

  • Choi, Un-Sook;Cho, Sung-Jin;Kim, Han-Doo;Kwon, Min-Jeong;Kim, Seok-Tae
    • The Journal of the Korea institute of electronic communication sciences
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    • v.11 no.9
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    • pp.885-892
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    • 2016
  • The nonlinear sequence generator called the shrinking generator was designed as nonlinear keystream generator composed by two maximum-length LFSRs. The shrunken sequences generated by the shrinking generator are included in the class of interleaved sequences and can be modelled as one of the output sequences of cellular automata (CA). In this paper, we propose a method for synthesizing a 90/150 CA-based sequence generator to generate a family of sequences with the same characteristic polynomial as the shrunken sequences.