Please use this identifier to cite or link to this item: http://hdl.handle.net/1959.14/29183
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- Title
- Algebraic attacks on SOBER-t32 and SOBER-t16 without stuttering
- Related
- International Workshop, Fast Software Encryption (11th : 2004) (5 - 7 February 2004 : Delhi, India)
- Related
- Roy, Bimal and Meier, Willi. Fast software encryption : 11th international workshop, FSE 2004 : revised papers, p.49-64
- DOI
- 10.1007/b98177
- Related
- Lecture notes in computer science Vol. 3017
- Publisher
- Germany : Springer-Verlag
- Date
- 2004
- Author/Creator
- Cho, Joo Yeon
- Author/Creator
- Pieprzyk, Josef
- Description
- This paper presents algebraic attacks on SOBER-t32 and SOBER-t16 without stuttering. For unstuttered SOBER-t32, two different attacks are implemented. In the first attack, we obtain multivariate equations of degree 10. Then, an algebraic attack is developed using a collection of output bits whose relation to the initial state of the LFSR can be described by low-degree equations. The resulting system of equations contains 2⁶⁹ equations and monomials, which can be solved using the Gaussian elimination with the complexity of 2¹⁹⁶.⁵. For the second attack, we build a multivariate equation of degree 14. We focus on the property of the equation that the monomials which are combined with output bit are linear. By applying the Berlekamp-Massey algorithm, we can obtain a system of linear equations and the initial states of the LFSR can be recovered. The complexity of attack is around O(2¹⁰⁰) with 2⁹² keystream observations. The second algebraic attack is applicable to SOBER-t16 without stuttering. The attack takes around O(2⁸⁵) CPU clocks with 2⁷⁸ keystream observations.
- Description
- 16 page(s)
- Subject Keyword
- algebraic attack
- Subject Keyword
- stream ciphers
- Subject Keyword
- linearization
- Subject Keyword
- NESSIE
- Subject Keyword
- SOBER-t32
- Subject Keyword
- SOBER-t16
- Subject Keyword
- modular addition
- Subject Keyword
- multivariate equations
- Resource Type
- conference paper
- Organisation
- Macquarie University. Dept. of Computing
- Identifier
- http://hdl.handle.net/1959.14/29183
- Identifier
- ISBN:9783540221715
- Identifier
- ISSN:0302-9743
- Identifier
- mq-rm-2004021396
- Language
- eng
- Reviewed
