Abstract
An iterative probabilistic method for reconstructing the initial state of RC4 keystream generator from a short segment of the keystream sequence is developed. The cryptanalytic algorithm consists of a forward and backward recursive computation of the posterior probabilities of the internal state components given a keystream segment. While maintaining the computational complexity, the new method presents a theoretical and practical improvement of a recently proposed method of a similar type, as less entries of the initial table are required to be known for the attack to be successful. If these entries have to be guessed, then the attack is expected to remain infeasible for the recommended word size of RC4.
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Golić, J.D. (2000). Iterative Probabilistic Cryptanalysis of RC4 Keystream Generator. In: Dawson, E.P., Clark, A., Boyd, C. (eds) Information Security and Privacy. ACISP 2000. Lecture Notes in Computer Science, vol 1841. Springer, Berlin, Heidelberg. https://doi.org/10.1007/10718964_18
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DOI: https://doi.org/10.1007/10718964_18
Publisher Name: Springer, Berlin, Heidelberg
Print ISBN: 978-3-540-67742-0
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