Algebraic analysis of the SSS stream cipher

Both the SSS and SOBER-t32 stream cipher designs use a single word-based shift register and a nonlinear filter function to produce keystream. In this paper we show that the algebraic attack method previously applied to SOBER-t32 is prevented from succeeding on SSS by the use of the key dependent substitution box (SBox) in the nonlinear filter of SSS. Additional assumptions and modifications to the SSS cipher in an attempt to enable algebraic analysis result in other difficulties that also render the algebraic attack infeasible. Based on these results, we conclude that a well chosen key-dependent substitution box used in the nonlinear filter of the stream cipher provides resistance against such algebraic attacks.

Measuring bitrate and quality trade-off in a fast region-of-interest based video coding

Prevailing video adaptation solutions change the quality of the video uniformly throughout the whole frame in the bitrate adjustment process; while region-of-interest (ROI)-based solutions selectively retains the quality in the areas of the frame where the viewers are more likely to pay more attention to. ROI-based coding can improve perceptual quality and viewer satisfaction while trading off some bandwidth. However, there has been no comprehensive study to measure the bitrate vs. perceptual quality trade-off so far. The paper proposes an ROI detection scheme for videos, which is characterized with low computational complexity and robustness, and measures the bitrate vs. quality trade-off for ROI-based encoding using a state-of-the-art H.264/AVC encoder to justify the viability of this type of encoding method. The results from the subjective quality test reveal that ROI-based encoding achieves a significant perceptual quality improvement over the encoding with uniform quality at the cost of slightly more bits. Based on the bitrate measurements and subjective quality assessments, the bitrate and the perceptual quality estimation models for non-scalable ROI-based video coding (AVC) are developed, which are found to be similar to the models for scalable video coding (SVC).

Group law computations on Jacobians of hyperelliptic Curves

We derive an explicit method of computing the composition step in Cantor’s algorithm for group operations on Jacobians of hyperelliptic curves. Our technique is inspired by the geometric description of the group law and applies to hyperelliptic curves of arbitrary genus. While Cantor’s general composition involves arithmetic in the polynomial ring F_q[x], the algorithm we propose solves a linear system over the base field which can be written down directly from the Mumford coordinates of the group elements. We apply this method to give more efficient formulas for group operations in both affine and projective coordinates for cryptographic systems based on Jacobians of genus 2 hyperelliptic curves in general form.

Action research as foresight methodology

To the action researcher, who laboriously spends his or her hours working within the local contexts of communities or organisations to co-generate meaningful research, and who’s theories are hardened on the anvil of creating meaningful social change; futures studies might seem the discipline the most peripheral to its interests, and the most ill equipped to deal with the local and intimate domain of community existence. To the futurist, who laboriously spends his or her hours understanding the nuances of history and social change, who through persistent work, begins to make sense of the weak signals and the subtle shifts, action research would seem as simply an auxiliary field, inappropriate for understanding the greater scheme. I invite the reader, however, whether they belong to one camp or the other, to let go of their respective disciplinary perspectives, and see both belonging to each other. [Introduction] .

Editors' introduction

In approaching this Special Issue on Foresight, Innovation and Entrepreneurship (FI&E) we considered that globalisation and rapid modernisation were increasingly creating the need for social reflexivity. We thought that in respect to the production and diffusion of innovations, both social and technical, that the landscape for new enterprise was characterised by widening change horizons and deeper ethical concerns. As a consequence of the greater demand for innovation to achieve economic prosperity, it was conceived that 'unforesightful' innovation may have irreparable affects on social and ecological systems and uncertain implications for our futures. Therefore, we considered a new intellectual alliance between FI&E was potentially a matter of human survival. New approaches to thinking about how and what we innovate, the choices we face for new enterprise creation and the influence of infrastructure for generating entrepreneurship, we considered, would need to emerge if we are to positively impact human and planetary sustainability in the 21st century. Hence this special issue was designed to bring together cross-disciplinary research aimed at exploring the synergies between foresight, innovation and entrepreneurship and the way in which these connections may be taking place in both the practical and theoretical sense.

Foresight practice in Australia: a meta-scan of practitioners and organisations

This critical review of foresight professionals seeks to analyse their social interests, methodology, epistemological focal domains, capacitating focus, geography and organisational type. The call for a deeper understanding of the practice in the Australian context is made in order for the foundations for a National Foresight Strategy to be laid.

From critique to cultural recovery: critical futures studies and casual layered analysis

Critical futures studies is not about the careers of a few scholars, rather it is about projects that transcend the narrow boundaries of the self. This biographical monograph examines the life and work of Richard Slaughter and Sohail Inayatullah.

From social foresight to social entrepreneurship: pathways to sustainability

This study asks the central question, ‘Are social entrepreneurs using foresight to create innovation based on triple bottom line sustainability measures?’ and ‘if so, how?’ Sustainability is the emergent criteria for evaluating many aspects of the social world, including corporate governance, health systems, economics, social welfare and the environment. All the while, innovation is one of the key factors in the constitution of our social worlds, be this legislative, organisational, social or technical change. Therefore, it appears that the drive toward sustainability should be coupled with an emphasis on innovation – in particular creating innovation toward sustainability. Yet unexamined assumptions exist behind such language. Sustainability is a concept within the context of ‘the future’, requiring one to question ‘what is the future’ – in essence a utilisation of the strategic capacity for foresight. Foresight, moreover, ranges from the tacit assumed personal foresight of the ordinary individual to the specialised foresight of the professional forecaster, scenario planner, or foresight practitioner.

Futures languages in Taiwan

Taiwan is a rapidly changing society, facing many challenges. In this state of flux, it is important to step back and see the big picture. The NewFutures 2000 conference, which commemorated fifty years of the of Tamkang University, in TamShui (the northernmost tip), Taiwan (Republic of China) and was held on 5–7 November 2000, gave Taiwanese an opportunity to gain just such a perspective. The ostensible aim of the conference was to explore ‘transformations in education, culture and technology’. But numerous perspectives and academic approaches were explored; predictions, normative visions, probable futures, alternative futures, ethical futures, epistemological re-constructions, studies and deconstruction’s of images of the future, myth and worldview—all received attention, sometimes overwhelming the participants with contradictory and overbearing ideas. [introduction]

Symposium of action learning: introduction

Action learning / research is a broad field of research with deep roots in the 20th century. Unlike futures studies, which is more content oriented (i.e., the futures of health, peace futures, global futures), action learning / research is process and methodology oriented – addressing the manner in which research is done, rather than what is researched. At its core it is collaborative learning for social change. This is particularly important because, in this age of heterogenous changes and multi-fold social challenges, we need to be able to bridge learning about our futures with action and innovation in the present, in a way that is effective and accessible for lay communities and organisations, not just experts. [Introduction]

Towards human and social innovation: not wanting to know in order to create

The formation of a venture relies, in part, upon the participants reaching a shared understanding of purpose and process. Yet in circumstances of great complexity and uncertainty how can such a shared understanding be created? If the response to complexity and uncertainty is to seek simplicity in order to find commonality then what is lost and what is at risk? Can shared understandings of purpose and process be arrived at by embracing complexity and uncertainty and if so how? These questions led us to explore the process of dialogue and communication of a team in its formative stages. Our interests were not centred upon the behavioural characteristics of the individuals in the 'forming' stage of group dynamics but rather the process of cognitive and linguistic turns, the wax and wan of ideas and, the formation of shared meaning. This process of cognitive and linguistic turns was focused thematically on the areas of foresight, innovation, entrepreneurship, and public policy. This cross disciplinary exploration sought to explore potential synergies between these domains, in particular in developing a conceptual basis for long term thinking that can inform wiser public policy.

Compact multiport antenna with isolated ports

The small element spacing of compact multiport arrays introduces strong mutual coupling between the antenna ports. Due to this coupling, the input impedance of the array changes when elements excitations are varied, and consequently, the array cannot be matched for an arbitrary excitation. Decoupling networks have in the past been used to provide an additional connection between antenna ports in order to cancel the coupling between elements. An alternative approach is to design the antenna so that each port does not excite a single element, but all elements simultaneously instead. The geometry of the antenna is optimized so that this direct excitation of elements counteracts the mutual coupling, thus yielding decoupled ports. This paper describes the design of such a 4-port antenna.

UWB antenna array for wireless transmission along corridors

A 2-element elliptical patch antenna array with a bi-directional radiation pattern has been developed for ultra wideband indoor wireless communications. The array is constructed by means of feeding two omni-directional elliptical patch elements with a 3-section hybrid power divider. Experimental results show that the array has a stable radiation pattern and low return loss over a broad bandwidth of 64% (3.1 - 6 GHz).