Abstract
We present a distinguishing attack against SOBER-128 with linear masking. We found a linear approximation which has a bias of 2− − 8.8 for the non-linear filter. The attack applies the observation made by Ekdahl and Johansson that there is a sequence of clocks for which the linear combination of some states vanishes. This linear dependency allows that the linear masking method can be applied. We also show that the bias of the distinguisher can be improved (or estimated more precisely) by considering quadratic terms of the approximation. The probability bias of the quadratic approximation used in the distinguisher is estimated to be equal to O(2− − 51.8), so that we claim that SOBER-128 is distinguishable from truly random cipher by observing O(2103.6) keystream words.
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
The home page for eSTREAM, http://www.ecrypt.eu.org/stream/
The home page for MUGI, http://www.sdl.hitachi.co.jp/crypto/mugi/index-e.html
The home page for SNOW, http://www.it.lth.se/cryptology/snow/
The home page for SOBER, http://www.qualcomm.com.au/Sober.html
Cho, J.Y., Pieprzyk, J.: Linear distinguishing attack on NLS. eSTREAM, ECRYPT Stream Cipher Project, Report 2006/018 (2006), http://www.ecrypt.eu.org/stream/papersdir/2006/018.pdf
Coppersmith, D., Halevi, S., Jutla, C.S.: Cryptanalysis of stream ciphers with linear masking. In: Yung, M. (ed.) CRYPTO 2002. LNCS, vol. 2442, pp. 515–532. Springer, Heidelberg (2002)
Ekdahl, P., Johansson, T.: Distinguishing attacks on SOBER-t16 and t32. In: Daemen, J., Rijmen, V. (eds.) FSE 2002. LNCS, vol. 2365, pp. 210–224. Springer, Heidelberg (2002)
Hawkes, P., Rose, G.: Primitive specification for SOBER-128 (April 2003), http://www.qualcomm.com.au/Sober128.html
Hawkes, P., Rose, G.: Primitive specification for NLS (April 2005), http://www.ecrypt.eu.org/stream/nls.html
Hawkes, P., Rose, G.: Sober. Primitive submitted to NESSIE by Qualcomm International (September 2000)
Author information
Authors and Affiliations
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 2006 Springer-Verlag Berlin Heidelberg
About this paper
Cite this paper
Cho, J.Y., Pieprzyk, J. (2006). Distinguishing Attack on SOBER-128 with Linear Masking. In: Batten, L.M., Safavi-Naini, R. (eds) Information Security and Privacy. ACISP 2006. Lecture Notes in Computer Science, vol 4058. Springer, Berlin, Heidelberg. https://doi.org/10.1007/11780656_3
Download citation
DOI: https://doi.org/10.1007/11780656_3
Publisher Name: Springer, Berlin, Heidelberg
Print ISBN: 978-3-540-35458-1
Online ISBN: 978-3-540-35459-8
eBook Packages: Computer ScienceComputer Science (R0)