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Analysis of Shrunken-Interleaved Sequence Based on Cellular Automata

셀룰라 오토마타 기반의 수축-삽입 수열의 분석

  • Received : 2010.05.13
  • Accepted : 2010.07.05
  • Published : 2010.10.30

Abstract

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.

스트림 암호시스템에 사용되는 불규칙 시각 제어 생성기인 수축수열 생성기는 두 개의 LFSR(Linear Feedback Shift Register)로 구성되며 이 생성기에 의해 생성되는 수열은 비선형수열임이 알려져 있다. 두 개의 최대길이를 갖는 90/150 셀룰라 오토마타 기반의 비선형수열 생성기는 각 셀에서 동일한 특성다항식을 갖는 의사 난수열을 효과적으로 생성할 수 있으므로 LFSR에 의해 생성되는 수열에 비하여 주기와 선형복잡도가 높은 비선형수열을 생성할 수 있다. 본 논문은 이러한 비선형수열에 대한 분석으로 90/150 셀룰라 오토마타 기반의 수축-삽입수열(shrunken-interleaved sequence)을 다룬다. 셀룰라 오토마타 기반의 비선형수열 생성기에 의해 생성되는 수축-삽입수열을 삽입수열로 분석이 가능함을 보이고 출력 수열의 일부를 알 때 알려지지 않은 새로운 출력 수열의 일부를 효과적으로 재구성하는 알고리즘을 제안한다.

Keywords

References

  1. A.J. Menezes, P.C. van Oorschot and S.A. Vanstone, Handbook of applied cryptography, CRC Press, 1997.
  2. D. Coppersmith, H. Krawczyk, and Y. Mansour, "The shrinking generator," Lecture Notes in Computer Science 773, pp. 22-39, 1993.
  3. W. Meier and O. Staffelbach, "The self-shrinking generator," Lecture Notes in Computer Science, Advanced in Cryptology Eurocrypt '94, pp. 205-214, 1995.
  4. S.A. Choi and K.C. Yang, "Balanced Shrinking Generator," Lecture Notes in Computer Science 2587, pp. 213-226, 2003.
  5. A.F. Sabater and D.G. Martinez, "Modelling nonlinear sequence generators in terms of linear cellular automata," Applied Mathematical Modelling, Vol. 31, pp. 226-235, 2007. https://doi.org/10.1016/j.apm.2005.08.013
  6. S.J. Cho, U.S. Choi, H.D. Kim, Y.H. Hwang, J.G. Kim and S.H. Heo, "New synthesis of one-dimensional 90/150 linear hybrid group cellular automata" IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems. Vol. 26(9), pp. 1720-1724, 2007. https://doi.org/10.1109/TCAD.2007.895784
  7. U.S. Choi, S.J. Cho, H.D. Kim, Y.H. Hwang and S.T. Kim, "Nonliear Pseudorandom Sequences Based on 90/150 LHGCA," Lecture Notes in Computer Science 5192, ACRI 2008, pp. 471-477, 2008.
  8. T. Siegenthaler, "Decrypting a class of stream ciphers using ciphertext-only," IEEE Transactions on Computers, Vol. C-34, pp. 81-85, 1985. https://doi.org/10.1109/TC.1985.1676518
  9. W. Meier and O. Staffelbach, "Fast correlation attacks on certain stream ciphers," Journal of Cryptology, Vol. 1(3), pp. 159-176, 1989. https://doi.org/10.1007/BF02252874
  10. B, Zhang, H. Wu, D. Feng and F. Bao, "A Fast Correlation Attack on the Shrinking Generator," CT-RSA 2005, Lecture Notes in Computer Science 3376, pp. 72-86, 2005.
  11. M. Hell and T. Johansson, "Two new attacks on the self-shrinking generator," IEEE Transactions on INformation Theory, Vol. 52(8), pp. 3837-3843, 2006. https://doi.org/10.1109/TIT.2006.878233
  12. B. Zhang and D. Feng, "New Guess-and-Determine Attack on the Self-Shrinking Generator," Lecture Notes in Computer Science 4284, Advances in Cryptology–ASIACRYPT 2006, pp. 54-68, 2006.
  13. A.F. Sabater and P.C. Gil, "Concatenated Automata in Cryptanalysis of Stream Ciphers," Lecture Notes in Computer Science 4173, ACRI 2006, pp. 611-616, 2006.
  14. A.F. Sabater and P.C. Gil, "Cryptanalytic Attack on Cryptographic Sequence Generators: The Class of Clock-Controlled Shrinking Generators," Lecture Notes in Computer Science 5073, Computational Science and Its Applications–ICCSA 2008, pp. 668-679, 2008
  15. A.F. Sabater, M.E. Pazo-Robles and P.C. Gil. "A simple linearization of the self-shrinking generator by means of cellular automata," Neural Networks Vol. 3. pp.461-464, 2010.
  16. R.J. McEliece, "Finite Fields for Computer Scientists and Engineers" Kluwer Academic Publishers, 1987.
  17. G. Gong, "Theory and applications of q-ary interleaved sequences," IEEE Transactions on Information Theory, Vol. 41, pp. 400-411, 1995. https://doi.org/10.1109/18.370141