Partial-indistinguishability obfuscation using braids

An obfuscator is an algorithm that translates circuits into functionally-equivalent similarly-sized circuits that are hard to understand. Efficient obfuscators would have many applications in cryptography. Until recently, theoretical progress has mainly been limited to no-go results. Recent works have proposed the first efficient obfuscation algorithms for classical logic circuits, based on a notion of indistinguishability against polynomial-time adversaries. In this work, we propose a new notion of obfuscation, which we call partial-indistinguishability. This notion is based on computationally universal groups with efficiently computable normal forms, and appears to be incomparable with existing definitions. We describe universal gate sets for both classical and quantum computation, in which our definition of obfuscation can be met by polynomial-time algorithms. We also discuss some potential applications to testing quantum computers. We stress that the cryptographic security of these obfuscators, especially when composed with translation from other gate sets, remains an open question.Comment: 21 pages,Proceedings of TQC 201

Factoring Products of Braids via Garside Normal Form

Braid groups are infinite non-abelian groups naturally arising from geometric braids. For two decades they have been proposed for cryptographic use. In braid group cryptography public braids often contain secret braids as factors and it is hoped that rewriting the product of braid words hides individual factors. We provide experimental evidence that this is in general not the case and argue that under certain conditions parts of the Garside normal form of factors can be found in the Garside normal form of their product. This observation can be exploited to decompose products of braids of the form ABC when only B is known. Our decomposition algorithm yields a universal forgery attack on WalnutDSA™, which is one of the 20 proposed signature schemes that are being considered by NIST for standardization of quantum-resistant public-key cryptography. Our attack on WalnutDSA™ can universally forge signatures within seconds for both the 128-bit and 256-bit security level, given one random message-signature pair. The attack worked on 99.8% and 100% of signatures for the 128-bit and 256-bit security levels in our experiments. Furthermore, we show that the decomposition algorithm can be used to solve instances of the conjugacy search problem and decomposition search problem in braid groups. These problems are at the heart of other cryptographic schemes based on braid groups.SCOPUS: cp.kinfo:eu-repo/semantics/published22nd IACR International Conference on Practice and Theory of Public-Key Cryptography, PKC 2019; Beijing; China; 14 April 2019 through 17 April 2019ISBN: 978-303017258-9Volume Editors: Sako K.Lin D.Publisher: Springer Verla

No credible evidence for links between 2D:4D and COVID-19 outcomes: A probabilistic perspective on digit ratio, ACE variants, and national case fatalities

Research into COVID-19 susceptibility and outcomes are critical, but claims must be carefully evaluated to inform policy decisions. In a recent series of articles, Manning and Fink [1–3] use national-level data to describe associations between case-fatality ratios and male and female finger ratios (2D:4D), a suggested measure of prenatal androgen exposure, as well as angiotensin-converting enzyme (ACE) allele and genotype frequencies. The authors suggest that 2D:4D is linked with ACE variant prevalence, and that higher male 2D:4D is associated with higher case fatality ratios, and point to 2D:4D as a useful prognostic measure for COVID-19 susceptibility. A critical review and robust Bayesian analysis of the hypothesis is described here, finding no conclusive evidence of COVID-19 mortality and 2D:4D, nor associations between 2D:4D and ACE1 allele or ACE2 genotype frequency. This absence of evidence is present for data taken from the second wave of COVID-19 in October 2020. Problematic theoretical grounding, individual-level conclusions drawn from national-level data, and issues with statistical inference in the original articles are discussed. Taken together, the current data offer no clear utility of 2D:4D in determining COVID-19 outcomes

In Search of Meaning:Lessons, Resources and Next Steps for Computational Analysis of Financial Discourse

We critically assess mainstream accounting and finance research applying methods from computational linguistics (CL) to study financial discourse. We also review common themes and innovations in the literature and assess the incremental contributions of work applying CL methods over manual content analysis. Key conclusions emerging from our analysis are: (a) accounting and finance research is behind the curve in terms of CL methods generally and word sense disambiguation in particular; (b) implementation issues mean the proposed benefits of CL are often less pronounced than proponents suggest; (c) structural issues limit practical relevance; and (d) CL methods and high quality manual analysis represent complementary approaches to analyzing financial discourse. We describe four CL tools that have yet to gain traction in mainstream AF research but which we believe offer promising ways to enhance the study of meaning in financial discourse. The four approaches are named entity recognition, summarization, semantics and corpus linguistics

Exploring the relationship between plural values of nature, human well‐being, and conservation and development intervention: Why it matters and how to do it?

Globally, land and seascapes across the bioculturally diverse tropics are in transition. Impacted by the demands of distant consumers, the processes of global environmental change and numerous interventions seeking climate, conservation and development goals, these transitions have the potential to impact the relationships and plurality of values held between people and place. This paper is a Synthesis of seven empirical studies within the Special Feature (SF): ‘What is lost in transition? Capturing the impacts of conservation and development interventions on relational values and human wellbeing in the tropics’. Through two Open Forum workshops, and critical review, contributing authors explored emergent properties across the papers of the SF. Six core themes were identified and are subsumed within broad categories of: (i) the problem of reconciling scale and complexity, (ii) key challenges to be overcome for more plural understanding of social dimensions of landscape change and (iii) ways forward: the potential of an environmental justice framework, and a practical overview of methods available to do so. The Synthesis interprets disparate fields and complex academic work on relational values, human well-being and de-colonial approaches in impact appraisal. It offers a practical and actionable catalogue of methods for plural valuation in the field, and reflects on their combinations, strengths and weaknesses. The research contribution is policy relevant because it builds the case for why a more plural approach in intervention design and evaluation is essential for achieving more just and sustainable futures, and highlights some of the key actions points deemed necessary to achieve such a transition to conventional practice

Acts of killing, acts of meaning:an application of corpus pattern analysis to language of animal-killing

We are currently witnessing unprecedented levels of ecological destruction and violence visited upon nonhumans. Study of the more-than-human world is now being enthusiastically taken up across a range of disciplines, in what has been called the ‘scholarly animal turn’. This thesis brings together concerns of Critical Animal Studies – along with related threads of posthumanism and new materialist thinking – and Corpus Linguistics, specifically Corpus Pattern Analysis (CPA), to produce a data-driven, lexicocentric study of the discourse of animal-killing. CPA, which has been employed predominantly in corpus lexicography, provides a robust and empirically well-founded basis for the analysis of verbs. Verbs are chosen as they act as the pivot of a clause; analysing them also uncovers their arguments – in this case, participants in material-discursive ‘killing’ events. This project analyses 15 ‘killing’ verbs using CPA as a basis, in what I term a corpus-lexicographical discourse analysis. The data is sampled from an animal-themed corpus of around 9 million words of contemporary British English, and the British National Corpus is used for reference. The findings are both methodological and substantive. CPA is found to be a reliable empirical starting point for discourse analysis, and the lexicographical practice of establishing linguistic ‘norms’ is critical to the identification of anomalous uses. The thesis presents evidence of anthropocentrism inherent in the English lexicon, and demonstrates several ways in which distance is created between participants of ‘killing’ constructions. The analysis also reveals specific ways that verbs can obfuscate, deontologise and deindividualise their arguments. The recommendations, for discourse analysts, include the adoption of CPA and a critical analysis of its resulting patterns in order to demonstrate the precise mechanisms by which verb use can either oppress or empower individuals. Social justice advocates are also alerted to potentially harmful language that might undermine their cause

The political economy of the management of industrial discontent in interwar Britain: the case of the National Unemployed Workers' Movement

In order to understand the capacity for state action, we also need to consider the way in which the state responds to different forms of dissent. Framed by Open Marxist theories of the state and the insights of the revolutionary school of industrial relations and trade unionism, this thesis explains the responses of the state and the trade unions towards the National Unemployed Workers' Movement between 1921 and 1939. It advances Keith Middlemas's argument on corporate bias, recognising that interwar British administrations continued integrating business and labour associations as intermediaries of the central government to avoid the arrival of crisis and guarantee governability and social order. But it goes further to suggest that the TUC fell short as a governing institution to contain labour unrest so the state had to use its coercive apparatus against the NUWM and the CPGB to prevent industrial agitation. It draws on archival research from across the United Kingdom in order to argue that the state and the labour movement legitimised each other and joined together to marginalise the NUWM to protect their fragile institutional arrangement. The thesis contributes to the literature on the National Unemployed Workers' Movement portraying it as an industrial, political movement and presenting new evidence on the action of the state against the NUWM and a distinctive analytical perspective of the manner in which the emergence of the movement disrupted an implicit agreement between the state, trade union's representatives and employers' associations aimed at the arrival of crisis. It also contributes to ongoing debates about the state management of discontent

Investigating the acquisition of the German passive by adult learners with L1 English in a formal learning environment : a learner corpus approach

This cross-disciplinary study draws on theories of linguistics, second language acquisition and language pedagogy in order to investigate the acquisition of the German passive by learners in a formal learning environment whose first language is English. This construction has hitherto received little attention from researchers, possibly because of the complexity of the available means of expressing it. The study focuses on the two periphrastic syntactic alternatives, each of which has a different semantic interpretation. With the general aim of identifying patterns in the learners’ usage of the construction over time, both synchronically and diachronically-collected data are assembled in a learner corpus and examined in a multi-method, multi-level study which differs from the single case study approach to language acquisition investigations which has often prevailed in the past. A quantitative, electronically-driven analysis is followed by a qualitative, judgement-based commentary. A comparative analysis of data from native speakers of German adds a further dimension to the discussion. Results of the analyses indicate differences between the written production of the two research populations and variation in the sequence of development and usage of the two German passives in the formal learning context which, it is suggested, may in part be due to the role played by instruction

Exploring the relationship between plural values of nature, human well-being, and conservation and development intervention: Why it matters and how to do it?

1. Globally, land and seascapes across the bioculturally diverse tropics are in transition. Impacted by the demands of distant consumers, the processes of global environmental change and numerous interventions seeking climate, conservation and development goals, these transitions have the potential to impact the relationships and plurality of values held between people and place. 2. This paper is a Synthesis of seven empirical studies within the Special Feature (SF): ‘What is lost in transition? Capturing the impacts of conservation and development interventions on relational values and human wellbeing in the tropics’. Through two Open Forum workshops, and critical review, contributing authors explored emergent properties across the papers of the SF. Six core themes were identified and are subsumed within broad categories of: (i) the problem of reconciling scale and complexity, (ii) key challenges to be overcome for more plural understanding of social dimensions of landscape change and (iii) ways forward: the potential of an environmental justice framework, and a practical overview of methods available to do so. 3. The Synthesis interprets disparate fields and complex academic work on relational values, human well-being and de-colonial approaches in impact appraisal. It offers a practical and actionable catalogue of methods for plural valuation in the field, and reflects on their combinations, strengths and weaknesses. 4. The research contribution is policy relevant because it builds the case for why a more plural approach in intervention design and evaluation is essential for achieving more just and sustainable futures, and highlights some of the key actions points deemed necessary to achieve such a transition to conventional practice