948 resultados para Walter Finkler


Relevância:

10.00% 10.00%

Publicador:

Resumo:

This paper presents a model for the generation of a MAC tag using a stream cipher. The input message is used indirectly to control segments of the keystream that form the MAC tag. Several recent proposals can be considered as instances of this general model, as they all perform message accumulation in this way. However, they use slightly different processes in the message preparation and finalisation phases. We examine the security of this model for different options and against different types of attack, and conclude that the indirect injection model can be used to generate MAC tags securely for certain combinations of options. Careful consideration is required at the design stage to avoid combinations of options that result in susceptibility to forgery attacks. Additionally, some implementations may be vulnerable to side-channel attacks if used in Authenticated Encryption (AE) algorithms. We give design recommendations to provide resistance to these attacks for proposals following this model.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Non-linear feedback shift register (NLFSR) ciphers are cryptographic tools of choice of the industry especially for mobile communication. Their attractive feature is a high efficiency when implemented in hardware or software. However, the main problem of NLFSR ciphers is that their security is still not well investigated. The paper makes a progress in the study of the security of NLFSR ciphers. In particular, we show a distinguishing attack on linearly filtered NLFSR (or LF-NLFSR) ciphers. We extend the attack to a linear combination of LF-NLFSRs. We investigate the security of a modified version of the Grain stream cipher and show its vulnerability to both key recovery and distinguishing attacks.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Woman abuse varies across intimate relationship categories (e.g., marriage, divorce, separation). However, it is unclear whether relationship status variations in violence against women differ across urban, suburban, and rural areas. We test the hypothesis that rural females, regardless of their intimate partner relationship status, are at higher risk of intimate violence than their urban and suburban counterparts. Results indicate that marital status is an important aspect of the relationship between intimate victimization and geographic area and that rural divorced and separated females are victimized at rates exceeding their urban counterparts.

Relevância:

10.00% 10.00%

Publicador:

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The signal processing techniques developed for the diagnostics of mechanical components operating in stationary conditions are often not applicable or are affected by a loss of effectiveness when applied to signals measured in transient conditions. In this chapter, an original signal processing tool is developed exploiting some data-adaptive techniques such as Empirical Mode Decomposition, Minimum Entropy Deconvolution and the analytical approach of the Hilbert transform. The tool has been developed to detect localized faults on bearings of traction systems of high speed trains and it is more effective to detect a fault in non-stationary conditions than signal processing tools based on envelope analysis or spectral kurtosis, which represent until now the landmark for bearings diagnostics.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

In the field of rolling element bearing diagnostics, envelope analysis has gained in the last years a leading role among the different digital signal processing techniques. The original constraint of constant operating speed has been relaxed thanks to the combination of this technique with the computed order tracking, able to resample signals at constant angular increments. In this way, the field of application of this technique has been extended to cases in which small speed fluctuations occur, maintaining high effectiveness and efficiency. In order to make this algorithm suitable to all industrial applications, the constraint on speed has to be removed completely. In fact, in many applications, the coincidence of high bearing loads, and therefore high diagnostic capability, with acceleration-deceleration phases represents a further incentive in this direction. This chapter presents a procedure for the application of envelope analysis to speed transients. The effect of load variation on the proposed technique will be also qualitatively addressed.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

In this paper we present a novel place recognition algorithm inspired by recent discoveries in human visual neuroscience. The algorithm combines intolerant but fast low resolution whole image matching with highly tolerant, sub-image patch matching processes. The approach does not require prior training and works on single images (although we use a cohort normalization score to exploit temporal frame information), alleviating the need for either a velocity signal or image sequence, differentiating it from current state of the art methods. We demonstrate the algorithm on the challenging Alderley sunny day – rainy night dataset, which has only been previously solved by integrating over 320 frame long image sequences. The system is able to achieve 21.24% recall at 100% precision, matching drastically different day and night-time images of places while successfully rejecting match hypotheses between highly aliased images of different places. The results provide a new benchmark for single image, condition-invariant place recognition.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The appropriation and elaborate re-working of mediated images and sound stand in a fluid relationship with established notions such as creativity, originality and artistic freedom. The evocative, recontextualised montage works of the eminent video artists Christian Marclay (The Clock) and Tracey Moffatt (Other; Love) may be viewed critically in the light of several theorists’ work, such as Walter Benjamin’s ideas on the crisis of reproduction and reactivation. The ironic pastiche, Do Look Now, a recent video installation work, is presented here as a similar dialogical intervention, representing a subversive deconstruction and critique of filmic codes and conventions, as well as being a new work crafted out of old film clips. (The films quoted in the work are listed here in an Appendix). These practical provocations are framed within a renewed, ‘queering’ investigation of creative works. Such an exploration is, arguably, both illuminating and liberating for particular practitioners and researchers engaged with the unpredictable intersections of creative meaning-making in a heavily legalised, mediated and digitised world.