Title:

Remarks on improved inversion attacks on nonlinear filter generators, Journal of Telecommunications and Information Technology, 2003, nr 4

Creator:

Górska, Anna ; Górski, Karol

Subject and Keywords:

shift registers ; nonlinear filter generator ; inversion attack ; stream cipher

Description:

The subject of this paper are inversion attacks on stream ciphers (nonlinear filter generators), which were first introduced by Golic [3] and extended by Golic, Clark and Dawson [4]. These original attacks have computational complexity O(2M), where M is the so-called “memory size” – distance between outer taps to filter function. In [6] we have proposed improved inversion attacks which have computational complexity O(2r -m) , where r denotes the length of the shift register and m denotes the largest gap between cells with taps to filter function or to connection polynomial. In this paper we describe further extension of our previous results obtained by considering shifts of the feedback polynomial which maximize the largest gap between cells with taps to filter function or to connection polynomial. We show that the previously proposed set of design criteria [3, 6] does not prevent the new version of improved inversion attack and we propose an additional criterion based on the relationship between positions of taps to filter function and positions of taps to the multiples of the connection polynomial.

Publisher:

Instytut Łączności - Państwowy Instytut Badawczy, Warszawa

Date:

2003, nr 4

Resource Type:

artykuł

Format:

application/pdf

Resource Identifier:

ISSN 1509-4553, on-line: ISSN 1899-8852

DOI:

10.26636/jtit.2003.4.207

ISSN:

1509-4553

eISSN:

1899-8852

Source:

Journal of Telecommunications and Information Technology

Language:

ang

Rights Management:

Biblioteka Naukowa Instytutu Łączności