Abstract
Here we study a weakness of the RC4 Key Scheduling Algorithm (KSA) that has already been noted by Mantin and Mironov. Consider the RC4 permutation S of N (usually 256) bytes and denote it by S N after the KSA. Under reasonable assumptions we present a simple proof that each permutation byte after the KSA is significantly biased (either positive or negative) towards many values in the range 0, ..., N − 1. These biases are independent of the secret key and thus present an evidence that the permutation after the KSA can be distinguished from random permutation without any assumption on the secret key. We also present a detailed empirical study over Mantin’s work when the theoretical formulae vary significantly from experimental results due to repetition of short keys in RC4. Further, it is explained how these results can be used to identify new distinguishers for RC4 keystream.
This is a preview of subscription content, log in via an institution to check access.
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
Preview
Unable to display preview. Download preview PDF.
References
Fluhrer, S.R., McGrew, D.A.: Statistical Analysis of the Alleged RC4 Keystream Generator. In: Schneier, B. (ed.) FSE 2000. LNCS, vol. 1978, pp. 19–30. Springer, Heidelberg (2001)
Fluhrer, S.R., Mantin, I., Shamir, A.: Weaknesses in the Key Scheduling Algorithm of RC4. In: Vaudenay, S., Youssef, A.M. (eds.) SAC 2001. LNCS, vol. 2259, pp. 1–24. Springer, Heidelberg (2001)
Golic, J.: Linear statistical weakness of alleged RC4 keystream generator. In: Fumy, W. (ed.) EUROCRYPT 1997. LNCS, vol. 1233, pp. 226–238. Springer, Heidelberg (1997)
Jenkins, R.J.: ISAAC and RC4 (1996), http://burtleburtle.net/bob/rand/isaac.html
Mantin, I., Shamir, A.: A Practical Attack on Broadcast RC4. In: Matsui, M. (ed.) FSE 2001. LNCS, vol. 2355, pp. 152–164. Springer, Heidelberg (2002)
Mantin, I.: A Practical Attack on the Fixed RC4 in the WEP Mode. In: Roy, B. (ed.) ASIACRYPT 2005. LNCS, vol. 3788, pp. 395–411. Springer, Heidelberg (2005)
Mantin, I.: Predicting and Distinguishing Attacks on RC4 Keystream Generator. In: Cramer, R.J.F. (ed.) EUROCRYPT 2005. LNCS, vol. 3494, pp. 491–506. Springer, Heidelberg (2005)
Mantin, I.: Analysis of the Stream Cipher RC4. Master’s Thesis. The Weizmann Institute of Science, Israel (2001)
Mironov, I.: Random Shuffles of RC4. In: Yung, M. (ed.) CRYPTO 2002. LNCS, vol. 2442, pp. 304–319. Springer, Heidelberg (2002)
Paul, G., Rathi, S., Maitra, S.: On Non-negligible Bias of the First Output Byte of RC4 towards the First Three Bytes of the Secret Key. In: 2007 International Workshop on Coding and Cryptography, pp. 285–294 (2007)
Paul, G., Maitra, S.: Permutation after RC4 Key Scheduling Reveals the Secret Key. In: SAC 2007. 14th Annual Workshop on Selected Areas in Cryptography, Ottawa, Canada (2007)
Paul, S., Preneel, B.: A New Weakness in the RC4 Keystream Generator and an Approach to Improve the Security of the Cipher. In: Roy, B., Meier, W. (eds.) FSE 2004. LNCS, vol. 3017, pp. 245–259. Springer, Heidelberg (2004)
Roos, A.: A class of weak keys in the RC4 stream cipher (1995), Available at http://marcel.wanda.ch/Archive/WeakKeys
Wagner, D.: My RC4 weak keys (1995), http://www.cs.berkeley.edu/~daw/my-posts/my-rc4-weak-keys
Author information
Authors and Affiliations
Editor information
Rights and permissions
Copyright information
© 2007 Springer-Verlag Berlin Heidelberg
About this paper
Cite this paper
Paul, G., Maitra, S., Srivastava, R. (2007). On Non-randomness of the Permutation After RC4 Key Scheduling. In: Boztaş, S., Lu, HF.(. (eds) Applied Algebra, Algebraic Algorithms and Error-Correcting Codes. AAECC 2007. Lecture Notes in Computer Science, vol 4851. Springer, Berlin, Heidelberg. https://doi.org/10.1007/978-3-540-77224-8_14
Download citation
DOI: https://doi.org/10.1007/978-3-540-77224-8_14
Publisher Name: Springer, Berlin, Heidelberg
Print ISBN: 978-3-540-77223-1
Online ISBN: 978-3-540-77224-8
eBook Packages: Computer ScienceComputer Science (R0)