This paper presents an empirical crypt-analytical method to analyse a partially known cipher algorithm. During cipher evaluation, it is always a challenge to make any decision on the strength of a partially known cipher algorithm, and if the algorithm is suitable for deployment. The core concept will be presented first, followed by an example to illustrate the idea. The idea is to focus on one ...

This paper presents generators based on decimated sequences of Generalized Feedback Shift Register (GFSR) generators. The equivalence relation between decimated GFSR generators and Tausworthe generators are presented and a k-distributed initialization scheme is derived. We present decimated GFSR generators that are maximally equidistributed. Timing results of these generators are presented.

New cyclic group codes oflength 2"1 over (m j)-bit symbols are introduced. These codes can be systematically encoded and decoded algebraically. The code rates are very close to Reed-Solomon (RS) codes and are much better than BoseChaudhuri-Hocquenghem (BCH) codes (a former alternative). The binary (m j)tuples are identified with a subgroup of the binary m-tuples which represent the field GF(2m)...

This paper presents a method for constructing n-stage Galois NLFSRs with period 2n − 1 from n-stage maximum length LFSRs. We introduce nonlinearity into state cycles by adding a nonlinear Boolean function to the feedback polynomial of the LFSR. Each assignment of variables for which this function evaluates to 1 acts as a crossing point for the LFSR state cycle. By adding a copy of the same func...

In this paper we show how the synchronous stream cipher Edon80 proposed as a candidate stream cipher in Profile 2 of the eSTREAM project, can be efficiently upgraded to synchronous stream cipher with authentication. We are achieving that by simple addition of two-bit registers into the e-transformers of Edon80 core, an additional 160-bit shift register and by putting additional communication lo...

D The results of a simulation study demonstrate that in linear feedback shift register-based built-in VLSI testing, the selection of proper feedback taps can reduce the test application time while retaining the testability goals

The Global System for Mobile communication, GSM voice calls are encrypted using a family of algorithms collectively called A5. A5/1 is the stream cipher which encrypts the information transmitted from mobile user. Initially A5 algorithm was kept secret to ensure the security but as algorithm was disclosed many cryptanalytic attacks were proposed and proved the A5 algorithm cryptographically wea...

In this report, a model of human sequence learning is developed called the linear associative shift register (LASR). LASR uses a simple error-driven associative learning rule to incrementally acquire information about the structure of event sequences. In contrast to recent modeling approaches, LASR describes learning as a simple and limited process. We argue that this simplicity is a virtue in ...

A family of keystream generators, called the LILI keystream generators, is proposed for use in stream cipher applications and the security of these generators is investigated with respect to currently known attacks. The design is simple and scalable, based on two binary linear feedback shift registers combined in a simple way, using both irregular clocking and nonlinear functions. The design pr...

In this paper we present a new algorithm for the recovery of the initial state of a linear feedback shift register when a noisy output sequence is given. Our work is focussed on the investigation of the asymptotical behaviour of the recovery process rather than on the construction of an optimal recovery procedure. Our results show the importance of low-weight checks and show also that the compl...