Skip to content
BY-NC-ND 3.0 license Open Access Published by De Gruyter May 18, 2016

Another look at normal approximations in cryptanalysis

  • Subhabrata Samajder and Palash Sarkar EMAIL logo

Abstract

Statistical analysis of attacks on symmetric ciphers often requires assuming the normal behaviour of a test statistic. Typically such an assumption is made in an asymptotic sense. In this work, we consider concrete versions of some important normal approximations that have been made in the literature. To do this, we use the Berry–Esséen theorem to derive explicit bounds on the approximation errors. A basic mathematical requirement is that such approximation errors should be within reasonable bounds, a point which appears to have been overlooked in many of the earlier works on statistical aspects of cryptanalysis. Interpreting the error bounds in the cryptanalytic context yields several surprising results. One important implication is that this puts in doubt the applicability of the order statistics based approach for analysing key recovery attacks on block ciphers. This approach has been earlier used to obtain several results on the data complexities of (multiple) linear and differential cryptanalysis. The non-applicability of the order statistics based approach puts a question mark on the data complexities obtained using this approach. Fortunately, we are able to recover all of these results by utilising the hypothesis testing framework. This, however, necessitates using normal approximations for the χ2 and the LLR test statistics considered in earlier works. These approximations themselves have issues which seem to be difficult to resolve satisfactorily. More generally, the message of our work is that all cryptanalytic attacks should properly derive and interpret the error bounds for any (normal) approximation that is made.

References

1 M. A. Abdelraheem, M. Ågren, P. Beelen and G. Leander, On the distribution of linear biases: Three instructive examples, Advances in Cryptology (CRYPTO 2012), Lecture Notes in Comput. Sci. 7417, Springer, Berlin (2012), 50–67. 10.1007/978-3-642-32009-5_4Search in Google Scholar

2 T. Baignères, P. Junod and S. Vaudenay, How far can we go beyond linear cryptanalysis?, Advances in Cryptology (ASIACRYPT 2004), Lecture Notes in Comput. Sci. 3329, Springer, Berlin (2004), 432–450. 10.1007/978-3-540-30539-2_31Search in Google Scholar

3 T. Baignères, P. Sepehrdad and S. Vaudenay, Distinguishing distributions using Chernoff information, Provable Security, Lecture Notes in Comput. Sci. 6402, Springer, Berlin (2010), 144–165. 10.1007/978-3-642-16280-0_10Search in Google Scholar

4 V. Bentkus, Dependence of the Berry–Esséen estimate on the dimension, Lithuanian Math. J. 26 (1986), 110–114. 10.1007/BF00966143Search in Google Scholar

5 A. C. Berry, The accuracy of the Gaussian approximation to the sum of independent variates, Trans. Amer. Math. Soc. 49 (1941), 122–136. 10.1090/S0002-9947-1941-0003498-3Search in Google Scholar

6 E. Biham and A. Shamir, Differential cryptanalysis of DES-like cryptosystems, Advances in Cryptology (CRYPTO'90), Lecture Notes in Comput. Sci. 537, Springer, Berlin (1990), 2–21. 10.1007/3-540-38424-3_1Search in Google Scholar

7 E. Biham and A. Shamir, Differential cryptanalysis of DES-like cryptosystems, J. Cryptology 4 (1991), 3–72. 10.1007/3-540-38424-3_1Search in Google Scholar

8 A. Biryukov, C. De Cannière and M. Quisquater, On multiple linear approximations, Advances in Cryptology (CRYPTO 2004), Lecture Notes in Comput. Sci. 3152, Springer, Berlin (2004), 1–22. 10.1007/978-3-540-28628-8_1Search in Google Scholar

9 C. Blondeau, A. Bogdanov and G. Leander, Bounds in shallows and in miseries, Advances in Cryptology (CRYPTO 2013), Lecture Notes in Comput. Sci. 8042, Springer, Berlin (2013), 204–221. 10.1007/978-3-642-40041-4_12Search in Google Scholar

10 C. Blondeau and B. Gérard, Multiple differential cryptanalysis: Theory and practice, Fast Software Encryption, Lecture Notes in Comput. Sci. 6733, Springer, Berlin (2011), 35–54. 10.1007/978-3-642-21702-9_3Search in Google Scholar

11 C. Blondeau, B. Gérard and K. Nyberg, Multiple differential cryptanalysis using LLR and χ2 statistics, Security and Cryptography for Networks, Lecture Notes in Comput. Sci. 7485, Springer, Berlin (2012), 343–360. 10.1007/978-3-642-32928-9_19Search in Google Scholar

12 C. Blondeau, B. Gérard and J.-P. Tillich, Accurate estimates of the data complexity and success probability for various cryptanalyses, Des. Codes Cryptogr. 59 (2011), 3–34. 10.1007/s10623-010-9452-2Search in Google Scholar

13 A. Bogdanov and E. Tischhauser, On the wrong key randomisation and key equivalence hypotheses in Matsui's algorithm 2, Fast Software Encryption, Lecture Notes in Comput. Sci. 8424, Springer, Berlin (2014), 19–38. 10.1007/978-3-662-43933-3_2Search in Google Scholar

14 J. Daemen and V. Rijmen, Probability distributions of correlation and differentials in block ciphers, J. Math. Crypt. 1 (2007), 221–242. 10.1515/JMC.2007.011Search in Google Scholar

15 F. C. Drost, W. C. M. Kallenberg, D. S. Moore and J. Oosterhoff, Power approximations to multinomial tests of fit, J. Amer. Statist. Assoc. 84 (1989), 130–141. 10.1080/01621459.1989.10478748Search in Google Scholar

16 C.-G. Esséen, On the Liapounoff limit of error in the theory of probability, Ark. Mat. Astron. Fys. A28 (1942), 1–19. Search in Google Scholar

17 C.-G. Esséen, A moment inequality with an application to the central limit theorem, Scand. Actuar. J. 1956 (1956), 160–170. 10.1080/03461238.1956.10414946Search in Google Scholar

18 W. Feller, An Introduction to Probability Theory and Its Applications, Vol. 2, John Wiley & Sons, New York, 2008. Search in Google Scholar

19 C. Harpes, G. G. Kramer and J. L. Massey, A generalization of linear cryptanalysis and the applicability of Matsui's piling-up lemma, Advances in Cryptology (EUROCRYPT'95), Lecture Notes in Comput. Sci. 921, Springer, Berlin (1995), 24–38. 10.1007/3-540-49264-X_3Search in Google Scholar

20 M. Hermelin, J. Y. Cho and K. Nyberg, Multidimensional extension of Matsui's algorithm 2, Fast Software Encryption, Lecture Notes in Comput. Sci. 5665, Springer, Berlin (2009), 209–227. 10.1007/978-3-642-03317-9_13Search in Google Scholar

21 N. L. Johnson, S. Kotz and N. Balakrishnan, Continuous Univariate Distributions, Vol. 1, 2nd ed., John Wiley & Sons, New York, 1994. Search in Google Scholar

22 N. L. Johnson, S. Kotz and N. Balakrishnan, Continuous Univariate Distributions, Vol. 2, 2nd ed., John Wiley & Sons, New York, 1995. Search in Google Scholar

23 P. Junod, On the optimality of linear, differential, and sequential distinguishers, Advances in Cryptology (EUROCRYPT 2003), Lecture Notes in Comput. Sci. 2656, Springer, Berlin (2003), 17–32. 10.1007/3-540-39200-9_2Search in Google Scholar

24 P. Junod and S. Vaudenay, Optimal key ranking procedures in a statistical cryptanalysis, Fast Software Encryption, Lecture Notes in Comput. Sci. 2887, Springer, Berlin (2003), 235–246. 10.1007/978-3-540-39887-5_18Search in Google Scholar

25 B. S. Kaliski Jr and M. J. B. Robshaw, Linear cryptanalysis using multiple approximations, Advances in Cryptology (Crypto'94), Lecture Notes in Comput. Sci. 839, Springer, Berlin (1994), 26–39. 10.1007/3-540-48658-5_4Search in Google Scholar

26 L. R. Knudsen, Truncated and higher order differentials, Fast Software Encryption, Lecture Notes in Comput. Sci. 1008, Springer, Berlin (1995), 196–211. 10.1007/3-540-60590-8_16Search in Google Scholar

27 G. Leander, On linear hulls, statistical saturation attacks, PRESENT and a cryptanalysis of PUFFIN, Advances in Cryptology (EUROCRYPT 2011), Lecture Notes in Comput. Sci. 6632, Springer, Berlin (2011), 303–322. 10.1007/978-3-642-20465-4_18Search in Google Scholar

28 I. Mantin and A. Shamir, A practical attack on broadcast RC4, Fast Software Encryption, Lecture Notes in Comput. Sci. 2355, Springer, Berlin (2002), 152–164. 10.1007/3-540-45473-X_13Search in Google Scholar

29 M. Matsui, Linear cryptanalysis method for DES cipher, Advances in Cryptology (EUROCRYPT'93), Lecture Notes in Comput. Sci. 765, Springer, Berlin (1993), 386–397. 10.1007/3-540-48285-7_33Search in Google Scholar

30 M. Matsui, The first experimental cryptanalysis of the data encryption standard, Advances in Cryptology (CRYPTO'94), Lecture Notes in Comput. Sci. 839, Springer, Berlin (1994), 1–11. 10.1007/3-540-48658-5_1Search in Google Scholar

31 S. Murphy, The independence of linear approximations in symmetric cryptanalysis, IEEE Trans. Inform. Theory 52 (2006), 5510–5518. 10.1109/TIT.2006.885528Search in Google Scholar

32 S. Murphy, F. Piper, M. Walker and P. Wild, Likelihood estimation for block cipher keys, Technical Report RHUL-MA-2006-3, Royal Holloway, University of London, 1995. Search in Google Scholar

33 V. V. Sazonov, On the multi-dimensional central limit theorem, Sankhya A 30 (1968), 181–204. Search in Google Scholar

34 A. A. Selçuk, On probability of success in linear and differential cryptanalysis, J. Cryptology 21 (2008), 131–147. 10.1007/s00145-007-9013-7Search in Google Scholar

35 A. Tardy-Corfdir and H. Gilbert, A known plaintext attack of FEAL-4 and FEAL-6, Advances in Cryptology (CRYPTO'91), Lecture Notes in Comput. Sci. 576, Springer, Berlin (1991), 172–181. 10.1007/3-540-46766-1_12Search in Google Scholar

36 I. S. Tyurin, An improvement of upper estimates of the constants in the Lyapunov theorem, Russian Math. Surveys 65 (2010), 201–202. 10.1070/RM2010v065n03ABEH004688Search in Google Scholar

37 A. M. Walker, A note on the asymptotic distribution of sample quantiles, J. R. Stat. Soc. Ser. B. Stat. Methodol. 30 (1968), 570–575. 10.1111/j.2517-6161.1968.tb00757.xSearch in Google Scholar

Received: 2016-1-30
Revised: 2016-4-27
Accepted: 2016-4-27
Published Online: 2016-5-18
Published in Print: 2016-6-1

© 2016 by De Gruyter

This article is distributed under the terms of the Creative Commons Attribution Non-Commercial License, which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

Downloaded on 2.6.2023 from https://www.degruyter.com/document/doi/10.1515/jmc-2016-0006/html
Scroll to top button