In this work we present a new structure for multiplication in finite fields. This structure is based on a digit-level LFSR (Linear Feedback Shift Register) multiplier in which the area of digit-multipliers are reduced using the Karatsuba method. We compare our results with the other works of the literature for F397 . We also propose new formulas for multiplication in F36·97 . These new formulas...

Built-In Self-Test (BIST), as the name suggests is a technique in which the circuit is capable of testing itself. This paper presents two techniques: Linear Feedback Shift Register (LFSR) and Cellular Automata (CA), used for test pattern generation and test response analysis in a typical BIST circuit. Both LFSR and CA are analyzed based on their construction and characteristics. A comparison of...

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)...

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...

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...

This paper presents an operational reconstruction technique of most stream ciphers. We primarily expose it for key-stream generators which consist of several linear feedback shift registers combined by a nonlinear Boolean function. It is shown how to completely recover the different feedback polynomials and the combining function, when the algorithm is totally unknown. This attack only requires...