Abstract
A new constrained edit distance computation algorithm is presented, as well as an algorithm for reconstruction of all the optimal and suboptimal paths in the array of partial constrained edit distances. The weight discrepancy of the suboptimal paths from the optimal ones does not overcome a threshold given in advance. The constraints include the maximum length of runs of deletions, the maximum length of runs of insertions and the total number of insertions. The edit operations are ordered in a sense that every substitution is preceded by at most one run of deletions followed by at most one run of insertions. This specific combination of constraints is determined by application of such a distance in cryptanalysis of pseudorandom sequence generators that employ decimation and interleaving of subgenerator sequences. Examples of generators from this family are the shrinking generator, the alternating step generator, the step 1/step 2 generator and so on. The search for the clock control sequence in such a generator is directed by relating the weight-difference threshold with the level of noise in the statistical model of the generator. In such a way, the efficiency of clock control sequence reconstruction is significantly improved. We show experimentally, on a problem of realistic size, that reconstruction of the clock control sequence in a generator from this family is feasible up to a relatively high level of noise in its statistical model.
Work partially supported by Ministerio de Ciencia y Tecnología (Spain) under grants SEG 2004-02418 and SEG 2004-04352-C04.03.
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References
Barkan, E., Biham, E., Keller, N.: Instant Ciphertext-Only Cryptanalysis of GSM Encrypted Communication, In: Boneh, D. (ed.) CRYPTO 2003. LNCS, vol. 2729, pp. 600–616. Springer, Heidelberg (2003)
Chambers, W., Golić, J.: Fast Reconstruction of Clock-Control Sequence. Electronics Letters 38(20), 1174–1175 (2002)
Chambers, W.G., Jennings, S.M.: Linear Equivalence of Certain BRM Shift-register Sequences. Electronics Letters 20(24), 1018–1019 (1984)
Coppersmith, D., Krawczyk, H., Mansour, Y.: The Shrinking Generator, Advances in Cryptology. In: Stinson, D.R. (ed.) CRYPTO 1993. LNCS, vol. 773, pp. 22–39. Springer, Heidelberg (1994)
Eppstein, D.: Finding the k-Shortest Paths. In: Proc. of the 35th IEEE Symposium on Foundations of Computer Science, Santa Fe, pp. 154–165 (1994)
Golić, J., Menicocci, R.: Edit Distance Correlation Attack on the Alternating Step Generator. In: Kaliski Jr., B.S. (ed.) CRYPTO 1997. LNCS, vol. 1294, pp. 499–512. Springer, Heidelberg (1997)
Golić, J., Mihaljević, M.: A Generalized Correlation Attack on a Class of Stream Ciphers Based on the Levenshtein Distance. Journal of Cryptology 3(3), 201–212 (1991)
Günther, C.G.: Alternating Step Generators Controlled by de Bruijn Sequences. In: Price, W.L., Chaum, D. (eds.) EUROCRYPT 1987. LNCS, vol. 304, pp. 5–14. Springer, Heidelberg (1988)
Hirschberg, D.: Serial Computations of Levenshtein Distances. In: Apostolico, A., Galil, Z. (eds.) Pattern Matching Algorithms, pp. 123–141. Oxford University Press, Oxford (1997)
Johansson, T.: Reduced Complexity Correlation Attacks on Two Clock-Controlled Generators. In: Ohta, K., Pei, D. (eds.) ASIACRYPT 1998. LNCS, vol. 1514, pp. 342–356. Springer, Heidelberg (1998)
Naor, D., Brutlag, D.: On Near-Optimal Alignments of Biological Sequences. J. Comput. Biology 1(4), 349–366 (1994)
Oommen, B.: Constrained String Editing. Inform. Sci. 40(9), 267–284 (1986)
Sankoff, D., Kruskal, J.B.: Time Warps, String Edits and Macromolecules: The Theory and Practice of Sequence Comparison. Addison Wesley, Reading (1983)
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Petrović, S., Fúster-Sabater, A. (2007). Reconstruction of Suboptimal Paths in the Constrained Edit Distance Array with Application in Cryptanalysis. In: Gervasi, O., Gavrilova, M.L. (eds) Computational Science and Its Applications – ICCSA 2007. ICCSA 2007. Lecture Notes in Computer Science, vol 4707. Springer, Berlin, Heidelberg. https://doi.org/10.1007/978-3-540-74484-9_52
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DOI: https://doi.org/10.1007/978-3-540-74484-9_52
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