Language-based Techniques for Practical and Trustworthy Secure Multi-party Computations

Secure Multi-party Computation (MPC) enables a set of parties to collaboratively compute, using cryptographic protocols, a function over their private data in a way that the participants do not see each other's data, they only see the final output. Typical MPC examples include statistical computations over joint private data, private set intersection, and auctions. While these applications are examples of monolithic MPC, richer MPC applications move between "normal" (i.e., per-party local) and "secure" (i.e., joint, multi-party secure) modes repeatedly, resulting overall in mixed-mode computations. For example, we might use MPC to implement the role of the dealer in a game of mental poker -- the game will be divided into rounds of local decision-making (e.g. bidding) and joint interaction (e.g. dealing). Mixed-mode computations are also used to improve performance over monolithic secure computations. Starting with the Fairplay project, several MPC frameworks have been proposed in the last decade to help programmers write MPC applications in a high-level language, while the toolchain manages the low-level details. However, these frameworks are either not expressive enough to allow writing mixed-mode applications or lack formal specification, and reasoning capabilities, thereby diminishing the parties' trust in such tools, and the programs written using them. Furthermore, none of the frameworks provides a verified toolchain to run the MPC programs, leaving the potential of security holes that can compromise the privacy of parties' data. This dissertation presents language-based techniques to make MPC more practical and trustworthy. First, it presents the design and implementation of a new MPC Domain Specific Language, called Wysteria, for writing rich mixed-mode MPC applications. Wysteria provides several benefits over previous languages, including a conceptual single thread of control, generic support for more than two parties, high-level abstractions for secret shares, and a fully formalized type system and operational semantics. Using Wysteria, we have implemented several MPC applications, including, for the first time, a card dealing application. The dissertation next presents Wys*, an embedding of Wysteria in F*, a full-featured verification oriented programming language. Wys* improves on Wysteria along three lines: (a) It enables programmers to formally verify the correctness and security properties of their programs. As far as we know, Wys* is the first language to provide verification capabilities for MPC programs. (b) It provides a partially verified toolchain to run MPC programs, and finally (c) It enables the MPC programs to use, with no extra effort, standard language constructs from the host language F*, thereby making it more usable and scalable. Finally, the dissertation develops static analyses that help optimize monolithic MPC programs into mixed-mode MPC programs, while providing similar privacy guarantees as the monolithic versions.

Investigating stratification, language diversity and mathematics classroom interaction

Research on the socio-political dimensions of language diversity in mathematics classrooms is under-theorised and largely focuses on language choice. These dimensions are, however, likely to influence mathematics classroom interaction in many other ways than participants’ choice of language. To investigate these influences, I propose that the notions ofheteroglossia, orders of indexicality and scale-jumping, can provide new theoretical tools with which to understand the links between classroom interaction and broader social patterns of marginalisation. To illustrate the utility of these ideas, I include some analysis of an episode observed in a sheltered elementary school second language mathematics classroom in Canada.

Novo método para estimativa do gradiente de fratura para poços de petróleo

The development of oil wells drilling requires additional cares mainly if the drilling is in offshore ultra deep water with low overburden pressure gradients which cause low fracture gradients and, consequently, difficult the well drilling by the reduction of the operational window. To minimize, in the well planning phases, the difficulties faced by the drilling in those sceneries, indirect models are used to estimate fracture gradient that foresees approximate values for leakoff tests. These models generate curves of geopressures that allow detailed analysis of the pressure behavior for the whole well. Most of these models are based on the Terzaghi equation, just differentiating in the determination of the values of rock tension coefficient. This work proposes an alternative method for prediction of fracture pressure gradient based on a geometric correlation that relates the pressure gradients proportionally for a given depth and extrapolates it for the whole well depth, meaning that theses parameters vary in a fixed proportion. The model is based on the application of analytical proportion segments corresponding to the differential pressure related to the rock tension. The study shows that the proposed analytical proportion segments reaches values of fracture gradient with good agreement with those available for leakoff tests in the field area. The obtained results were compared with twelve different indirect models for fracture pressure gradient prediction based on the compacting effect. For this, a software was developed using Matlab language. The comparison was also made varying the water depth from zero (onshore wellbores) to 1500 meters. The leakoff tests are also used to compare the different methods including the one proposed in this work. The presented work gives good results for error analysis compared to other methods and, due to its simplicity, justify its possible application

Poetry and the limits of language

This essay argues that poetic language offers the possibility of meaning and value, and simultaneously points beyond itself, to the limits of language, to a space differently configured as erasure, silence, the unsignifiable. What does it suggest, epistemologically and ontologically, if we acknowledge this double action of poetic language? What might this space beyond language be, and what difference does it make if we acknowledge this space? The essay examines four poems and the different ways in which they acknowledge such a space, drawing on the historically distinct approaches of Meister Eckhart and Jacques Derrida in order to ask what the space beyond language might be. The argument of the essay is that in acknowledging such a space something opens up for writers and readers of poetry: a different approach to knowing, and a potentially humbled ontological position.

Primary teachers notice the impact of language on children’s mathematical reasoning

Mathematical reasoning is now featured in the mathematics curriculum documents of many nations, but this necessitates changes to teaching practice and hence a need for professional learning. The development of children’s mathematical reasoning requires appropriate encouragement and feedback from their teacher who can only do this if they recognise mathematical reasoning in children’s actions and words. As part of a larger study, we explored whether observation of educators conducting mathematics lessons can develop teachers’ sensitivity in noticing children’s reasoning and consideration of how to support reasoning. In the Mathematical Reasoning Professional Learning Research Program, demonstration lessons were conducted in Australian and Canadian primary classrooms. Data sources included post-lesson group discussions. Observation of demonstration lessons and engagement in post-lesson discussions proved to be effective vehicles for developing a professional eye for noticing children’s individual and whole-class reasoning. In particular, the teachers noticed that children struggled to employ mathematical language to communicate their reasoning and viewed limitations in language as a major barrier to increasing the use of mathematical reasoning in their classrooms. Given the focus of teachers’ noticing of the limitations in some types of mathematical language, it seems that targeted support is required for teachers to facilitate classroom discourse for reasoning.

Development of a framework to create plugins in Android Apps

The present work aims to allow developers to implement small features on a certain Android application in a fast and easy manner, as well as provide their users to install them ondemand, i.e., they can install the ones they are interested in. These small packages of features are called plugins, and the chosen development language to develop these in was JavaScript. In order to achieve that, an Android framework was developed that enables the host application to install, manage and run these plugins at runtime. This framework was designed to have a very clean and almost readable API, which allowed for better code organization and maintainability. The implementation used the Google’s engine “V8” to interpret the JavaScript code and through a set of JNI calls made that code call certain Android methods previously registered in the runtime. In order to test the framework, it was integrated with the client’s communication application RCS+ using two plugins developed alongside the framework. Although these plugins had only the more common requirements, they were proven to work successfully as intended. Concluding, the framework although successful made it clear that this kind of development through a non-native API has its set of difficulties especially regarding the implementation of complex features.

The Weight of Language and Action: Epistemic Stance, Methodological Action,and Theoretical Perspective in Knowledge Organization

Knowledge organization (KO) research is a field of scholarship concerned with the design, study and critique of the processes of organizing and representing documents that societies see as worthy of preserving (Tennis, 2008). In this context we are concerned with the relationship between language and action.On the one hand, we are concerned with what language can and does do for our knowledge organization systems (KOS). For example, how do the words NEGRO or INDIAN work in historical and contemporary indexing languages? In relation to this, we are also concerned with how we know about knowledge organization (KO) and its languages. On the other hand, we are concerned with how to act given this knowledge. That is, how do we carry out research and how do we design, implement, and evaluate KO systems?It is important to consider these questions in the context of our work because we are delegated by society to disseminate cultural memory. We are endowed with a perspective, prepared by an education, and granted positions whereby society asks us to ensure that documentary material is accessible to future generations. There is a social value in our work, and as such there is a social imperative to our work. We must act with good conscience, and use language judiciously, for the memory of the world is a heavy burden.In this paper, I explore these two weights of language and action that bear down on KO researchers. I first summarize what extant literature says about the knowledge claims we make with regard to KO practices and systems. To make it clear what it is that I think we know, I create a schematic that will link claims (language) to actions in advising, implementing, or evaluating information practices and systems.I will then contrast this with what we do not know, that is, what the unanswered questions might be (Gnoli, 2008 ; Dahlberg, 2011), and I will discuss them in relation to the two weights in our field of KO.Further, I will try to provide a systematic overview of possible ways to address these open questions in KO research. I will draw on the concept of elenchus - the forms of epistemology, theory, and methodology in KO (Tennis, 2008), and framework analysis which are structures, work practice, and discourses of KO systems (Tennis, 2006). In so doing, I will argue for a Neopragmatic stance on the weight of language and action in KO (Rorty, 1982 ; 2000). I will close by addressing the lacuna left in Neopragmatic thought – the ethical imperative to use language and action in a particular good and moral way. That is, I will address the ethical imperative of KO given its weights, epistemologies, theories, and methods. To do this, I will review a sample of relevant work on deontology in both western and eastern philosophical schools (e.g., Harvey, 1995).The perspective I want to communicate in this section is that the good in carrying out KO research may begin with epistemic stances (cf., language), but ultimately stands on ethical actions. I will present an analysis describing the micro and the macro ethical concerns in relation to KO research and its advice on practice. I hope this demonstrates that the direction of epistemology, theory, and methodology in KO, while burdened with the dual weights of language and action, is clear when provided an ethical sounding board. We know how to proceed when we understand how our work can benefit the world.KO is an important, if not always understood, division of labor in a society that values its documentary heritage and memory institutions. Being able to do good requires us to understand how to balance the weights of language and action. We must understand where we stand and be able to chart a path forward, one that does not cause harm, but adds value to the world and those that want to access recorded knowledge.

Young children as rule makers

Young children engage in a constant process of negotiating and constructing rules, utilizing these rules as cultural resources to manage their social interactions. This paper examines how young children make sense of, and also construct, rules within one early childhood classroom. This paper draws on a recent study conducted in Australia, in which video-recorded episodes of young children’s talk-in-interaction were examined. Analysis revealed four interactional practices that the children used, including manipulating materials and places to claim ownership of resources within the play space; developing or using pre-existing rules and social orders to control the interactions of their peers; strategically using language to regulate the actions of those around them; and creating and using membership categories such as ‘car owner’ or ‘team member’ to include or exclude others and also to control and participate in the unfolding interaction. While the classroom setting was framed within adult conceptions and regulations, analysis of the children’s interaction demonstrated their co-constructions of social order and imposition of their own forms of rules. Young children negotiated both adult constructed social order and also their own peer constructed social order, drawing upon various rules within both social orders as cultural resources by which they managed their interaction.

Losing their marbles : syntax-free programming for assessing problem-solving skills

Novice programmers have difficulty developing an algorithmic solution while simultaneously obeying the syntactic constraints of the target programming language. To see how students fare in algorithmic problem solving when not burdened by syntax, we conducted an experiment in which a large class of beginning programmers were required to write a solution to a computational problem in structured English, as if instructing a child, without reference to program code at all. The students produced an unexpectedly wide range of correct, and attempted, solutions, some of which had not occurred to their teachers. We also found that many common programming errors were evident in the natural language algorithms, including failure to ensure loop termination, hardwiring of solutions, failure to properly initialise the computation, and use of unnecessary temporary variables, suggesting that these mistakes are caused by inexperience at thinking algorithmically, rather than difficulties in expressing solutions as program code.

Social scientists don’t say titwank’

Drawing on the textual evidence of a number of referees’ reports, this article maps key differences between the humanities and social sciences approaches to the study of pornography, in order to facilitate better understanding and communication between the areas. 1. Social scientists avoid ‘vulgar’ language to describe sex. Humanities scholars need not do so. 2. Social scientists remain committed to the idea of ‘objectivity’ while humanities scholars reject the idea – although this may be a confusion in language, with the term in the social sciences used to mean something more like ‘falsifiability’. 3. Social science assumes that the primary effects of exposure to pornography must be negative. 4. More generally, social science resists paradigm changes, insisting that all new work agrees with research that has gone before. 5. Social science believes that casual sex and sadomasochism are negative; humanities research need not do so.

Using SITDRM for Privacy Rights Management

SITDRM 1 is a privacy protection system that protects private data through the enforcement of MPEG REL licenses provided by consumers. Direct issuing of licenses by consumers has several usability problems that will be mentioned in this paper. Further, we will describe how SITDRM incorporates P3P language to provide a consumer-centered privacy protection system.

Leveraging managed frameworks from modular languages

Managed execution frameworks, such as the.NET Common Language Runtime or the Java Virtual Machine, provide a rich environment for the creation of application programs. These execution environments are ideally suited for languages that depend on type-safety and the declarative control of feature access. Furthermore, such frameworks typically provide a rich collection of library primitives specialized for almost every domain of application programming. Thus, when a new language is implemented on one of these frameworks it becomes necessary to provide some kind of mapping from the new language to the libraries of the framework. The design of such mappings is challenging since the type-system of the new language may not span the domain exposed in the library application programming interfaces (APIs). The nature of these design considerations was clarified in the implementation of the Gardens Point Component Pascal (gpcp) compiler. In this paper we describe the issues, and the solutions that we settled on in this case. The problems that were solved have a wider applicability than just our example, since they arise whenever any similar language is hosted in such an environment.

The coming

Through an exploration of representations of metamorphosis and the creation of a body of written work, this thesis uses a critical examination of theoretical approaches to metamorphosis in combination with textual analysis of representations of metamorphosis and creative practice as research to arrive at the beginnings of an ethic of writing. The creative work, The Coming, consists of a collection of short fiction, The Coming, and two collections of poetry, Orison and Milagros. The exegesis, Transhuman Change: towards an ethic of writing, explores theories about metamorphosis as a figure for writing, as a trope, and as a motif for exploring identity to contextualise the analysis of representations of metamorphosis from which the ethic is developed. With reference to the psychosexual development theory of Jacques Lacan and Elaine Scarry’s philosophy of the body, pain, language and creativity, the exegesis examines existing approaches to metamorphosis and uses supplementary textual analysis of influential representations of metamorphosis from Ovid to Pygmalion, X-Men and Extreme Makeover to explore assumptions about the body, language, the self, gender in western culture. The limitations of the performance of representations of metamorphosis as a figure for the self’s survival of death are considered in the light of voice as metonym for self to propose an ethic which valorises life. The experience of sex and the construction of gender in representations of metamorphosis are considered in the light of Lacan’s theory of desire and Scarry’s theory of the body and language to propose an ethic of representing gender ironically. The motif of the faithless lover and the Pygmalion myth are considered in the light of the (m)other’s role in language to propose an ethic in which indeterminacy constitutes the condition for being aware of oneself among selves. Each of the three proposals is discussed in relation to the short fiction, memoir and poems produced in the course of this research to test their limits and possibilities as the foundation of an emerging ethic of writing.

Improving reflective writing in higher education : A social semiotic perspective

Reflective skills are widely regarded as a means of improving students’ lifelong learning and professional practice in higher education (Rogers 2001). While the value of reflective practice is widely accepted in educational circles, a critical issue is that reflective writing is complex, and has high rhetorical demands, making it difficult to master unless it is taught in an explicit and systematic way. This paper argues that a functional-semantic approach to language (Eggins 2004), based on Halliday’s (1978) systemic functional linguistics can be used to develop a shared language to explicitly teach and assess reflective writing in higher education courses. The paper outlines key theories and scales of reflection, and then uses systemic functional linguistics to develop a social semiotic model for reflective writing. Examples of reflective writing are analysed to show how such a model can be used explicitly to improve the reflective writing skills of higher education students.

Research Ethics and Creative Arts Hypothetical

The merits of a research project are commonly framed in terms of perceived benefits with respect to knowledge production, wellbeing, the social good, and so on. Such measures can, however, be at odds with certain types of creative practice, which may be perceived as frivolous, unsettling, or shocking. Moreover, creative practice research methodologies commonly eschew more traditional research conventions. In exploring these tensions, this live performance event (including a DVD component) adapted key dramatic principles developed in Geoffrey Robertson's groundbreaking Hypotheticals. The event was presented for an audience of staff and students at QUT's Creative Industries Faculty in July 2010. It confirmed Dr Angela Romano's contention that: “Part of the ethical clearance process for practice-led researchers will be to find a language to explain the methodology, significance, merit and integrity of their research to people outside their field of practice.” (Angela Romano, QUT Creative Industries) “Part of the ethical clearance process for practice-led researchers will be to find a language to explain the methodology, significance, merit and integrity of their research to people outside their field of practice.”