corrective feedback (cf) and its different types have long absorbed many scholars and practitioners. as ellis (2009) mentioned some experimental studies need to be carefully designed to discover the relative effectiveness of each of these cf techniques. the goal of this qualitative study was to discover whether the employment of different cf strategies could bring about an attitudinal shift. to...

orthogonal frequency division multiplexing (ofdm) has become a promising method for many wireless communication applications. however, one main drawback of ofdm systems is the high peak-to-average power ratio (papr). selected mapping (slm) is a well-known technique to decrease the problem of high papr in ofdm systems. in this method, transmitter is obliged to send some bits named side informati...

Feedback shift registers with carry operation (FCSR's) are described, implemented, and analyzed with respect to memory requirements, initial loading, period, and distributional properties of their output sequences. Many parallels with the theory of linear feedback shift registers (LFSR's) are presented, including a synthesis algorithm (analogous to the Berlekamp-Massey algorithm for LFSR's) whi...

A standard model of nonlinear combiner generator for stream cipher system combines the outputs of several independent Linear Feedback Shift Register (LFSR) sequences using a nonlinear Boolean function to produce the key stream. Given such a model, cryptanalytic attacks have been proposed by finding the sparse multiples of the connection polynomials corresponding to the LFSRs. In this direction ...

In spread spectrum systems, pseudo-random (PN) sequences are used to spread the data bits. There are various type of PN sequences are available with good correlation properties, most of which are generated by Linear Feedback Shift Register (LFSR). In this paper we describe the generation pseudo chaotic sequences (PCS) and conventional PN sequences and its correlation properties. Here, pseudo-ch...

KATAN and KTANTAN are two lightweight families of hardware oriented block ciphers proposed by Cannière et al. at CHES 2009. They have different versions of 32-, 48and 64-bit state, all of which work with an 80-bit key. Inspired by the Trivium stream cipher, these families have an innovative structure based on two non-linear feedback shift registers. Such a structure attracts the attention of cr...

SUMMARY Spreading sequences with appropriate negative auto-correlation can reduce average multiple access interference (MAI) in asyn-chronous DS/CDMA systems compared with the conventional Gold Sequences generated by linear feedback shift registers (LFSRs). We design spreading sequences with negative auto-correlation based on Gold sequences and the chaos theory for the Bernoulli map. By compute...

Compressed sensing is a novel technique where one can recover sparse signals from the undersampled measurements. In this correspondence, a K×N measurement matrix for compressed sensing is deterministically constructed via additive character sequences. The Weil bound is then used to show that the matrix has asymptotically optimal coherence for N = K, and to present a sufficient condition on the ...

In this paper, we propose a novel technique, called multi-output filtering model, to study the non-randomness property of a cryptographic algorithm such as message authentication codes and block ciphers. A multi-output filtering model consists of a linear feedback shift register (LFSR) and a multi-output filtering function. Our contribution in this paper is twofold. First, we propose an attack ...

INTRODUCTION In an important class of stream ciphers, called combination generators, the key stream is produced by combining the outputs of several independent Linear Feedback Shift Register (LFSR) sequences with a nonlinear Boolean function. Siegenthaler [12] was the first to point out that the combining function should possess certain properties in order to resist divide-and-conquer attacks.A...