The Common HOL Platform

The Common HOL project aims to facilitate porting source code and proofs between members of the HOL family of theorem provers. At the heart of the project is the Common HOL Platform, which defines a standard HOL theory and API that aims to be compatible with all HOL systems. So far, HOL Light and hol90 have been adapted for conformance, and HOL Zero was originally developed to conform. In this paper we provide motivation for a platform, give an overview of the Common HOL Platform's theory and API components, and show how to adapt legacy systems. We also report on the platform's successful application in the hand-translation of a few thousand lines of source code from HOL Light to HOL Zero.Comment: In Proceedings PxTP 2015, arXiv:1507.0837

On the genesis of computer forensis

This thesis presents a coherent set of research contributions to the new discipline of computer forensis. It analyses emergence of computer forensis and defines challenges facing this discipline, carries forward research advances in conventional methodology, introduces novel approach to using virtual environments in forensis, and systemises the computer forensis body of knowledge leading to the establishment of tertiary curriculum. The emergence of computer forensis as a separate discipline of science was triggered by evolution and growth of computer crime. Computer technology reached a stage when a conventional, mechanistic approach to collecting and analysing data is insufficient: the existing methodology must be formalised, and embrace technologies and methods that will enable the inclusion of transient data and live systems analysis. Further work is crucial to incorporate advances in related disciplines like computer security and information systems audit, as well as developments in operating systems to make computer forensics issues inherent in their design. For example: it is proposed that some of the features offered by persistent systems could be built into conventional operating systems to make illicit activities easier to identify and analyse. The analysis of permanent data storage is fundamental to computer forensics practice. There is very little finalised, and a lot still to be discovered in the conventional computer forensics methodology. This thesis contributes to formalisation and improved integrity of forensic handling of data storage by: formalising methods for data collection and analysis in NTFS (Microsoft file system) environment: presenting safe methodology for handling data backups in order to avoid information loss where Alternate Data Streams (ADS) are present: formalising methods of hiding and extracting hidden and encrypted data. A significant contribution of this thesis is in the field of application of virtualisation, or simulation of the computer in the virtual environment created by the underlying hardware and software, to computer forensics practice. Computer systems are not easily analysed for forensic purpose, and it is demonstrated that virtualisation applied in computer forensics allows for more efficient and accurate identification and analysis of the evidence. A new method is proposed where two environments used in parallel can bring faster and verifiable results not dependent on proprietary, close source tools and may lead to gradual shift from commercial Windows software to open source software (OSS). The final contribution of this thesis is systemising the body of knowledge in computer forensics, which is a necessary condition for it to become an established discipline of science. This systemisation led to design and development of tertiary curriculum in computer forensics illustrated here with a case study of computer forensics major for Bachelor of Computer Science at University of Western Sydney. All genesis starts as an idea. A natural part of scientific research process is replacing previous assumptions, concepts, and practices with new ones which better approximate the truth. This thesis advances computer forensis body of knowledge in the areas which are crucial to further development of this discipline. Please note that the appendices to this thesis consist of separately published items which cannot be made available due to copyright restrictions. These items are listed in the PDF attachment for reference purposes

An Introduction to Voting Rule Verification

We give an introduction to deductive verification methods that can be used to formally prove that voting rules and their implementations satisfy specified properties and conform to the desired democratic principles. In the first part of the paper we explain the basic principles: We describe how first-order logic with theories can be used to formalise the desired properties. We explain the difference between (1) proving that one set of properties implies another property, (2) proving that a voting rule implementation has a certain property, and (3) proving that a voting rule implementation is a refinement of an executable specification. And we explain the different technologies: (1) SMT-based testing, (2) bounded program verification, (3) relational program verification, and (4) symmetry breaking. In this first part of the paper, we also explain the difference between verifying functional and relational properties (such as symmetries). In the second part, we present case studies, including (1) the specification and verification of semantic properties for an STV rule used for electing the board of trustees for a major international conference and (2) the deduction-based computation of election margins for the Danish national parliamentary elections

Good enough for governance? Audit and marine biodiversity offsetting in Australia

Biodiversity offsetting is often presented as a way to manage competing demands of environmental protection and economic development. It is premised on the transparent demonstration of how aims of no net loss of biodiversity (NNL) or similar are met in practice. This is complicated in marine systems where ecological predictions are commonly highly uncertain, knowledge of ecological restoration is low and administrative governance is complex. Drawing on a case study of marine biodiversity offsetting in Australia, this paper shows how these uncertainties pose practical challenges for both producers and consumers of marine biodiversity offsets, needing to progress with decision-making while meeting increasing societal pressure for demonstrable NNL. These competing needs are met through the centrality of an auditable decision-making process that contributes to establishing an organisation’s social licence to operate. The need for auditability drives the use of an imprecise measure of NNL through financial equivalency and the use of strategic offsetting projects. The coarse-grained interpretation of biodiversity offsetting best practice reduces the risks posed by explicit acknowledgement of biodiversity loss, offset failure or prohibitively large offset liabilities. Strategic relationship management across government, industry, academia and non-governmental organisations has raised the profile of biodiversity and its importance, but whether the auditing process has delivered on environmental protection is an open question. What is ‘good enough’ to meet governance standards may have become the over-riding goal. We conclude by acknowledging that the seemingly unattainable yet expected aim of NNL for marine systems prioritises auditability above discussions of ‘acceptable’ risk

Software reliability and dependability: a roadmap

Shifting the focus from software reliability to user-centred measures of dependability in complete software-based systems. Influencing design practice to facilitate dependability assessment. Propagating awareness of dependability issues and the use of existing, useful methods. Injecting some rigour in the use of process-related evidence for dependability assessment. Better understanding issues of diversity and variation as drivers of dependability. Bev Littlewood is founder-Director of the Centre for Software Reliability, and Professor of Software Engineering at City University, London. Prof Littlewood has worked for many years on problems associated with the modelling and evaluation of the dependability of software-based systems; he has published many papers in international journals and conference proceedings and has edited several books. Much of this work has been carried out in collaborative projects, including the successful EC-funded projects SHIP, PDCS, PDCS2, DeVa. He has been employed as a consultant t

The role of context in decolonising engineering curriculums in proudly South African universities: a cybernetic perspective

Abstract: This paper addresses the epistemological challenges facing South African Public Universities in light of the #FeesMustFall campaign and the associated outcomes. Of particular interest are the academics who are to embrace the changes while they remain in the education system. The decolonisation of knowledge, which is still not clearly understood nor agreed upon, necessitates a rapid review of the status quo in the major universities and how they conduct their business. While transformation and decolonisation are not synonymous, the universities will be undergoing transformation to address the decolonisation needs of the majority of its students, which has already created dilemmas for the academics who have largely followed a Eurocentric approach, and are now to implement the changes addressing decolonisation. The immediate aspects facing the academics are the undefined curriculum changes, as well as the new teaching and learning strategies, which need to reflect the epistemology of the students addressing an Afrocentricity that has not been embraced in the past. A cybernetic perspective relying on Pask’s Conversation Theory may be integral in allowing the academics the skill to contextualise the curriculum, embracing those who are the consumers of this new co-created locally generated knowledge

Checking property preservation of refining transformations for model-driven development

In Model-Driven Software Development, a software product is created through iteratively refined modelling. It is crucial that this process preserves certain desirable properties of the initial model. However, checking this is increasingly difficult as the models are increasingly more refined. We propose an incremental model checking technique to determine the preservation of safety and liveness properties in models of concurrent systems with respect to changes applied on individual processes, formalised as transformations of Labelled Transition Systems. The preservation check involves checking bisimilarity between transformed and new behaviour, and never involves reexploring unchanged behaviour. We prove its correctness and demonstrate its applicability

Good enough for governance? Audit and marine biodiversity offsetting in Australia

Biodiversity offsetting is often presented as a way to manage competing demands of environmental protection and economic development. It is premised on the transparent demonstration of how aims of no net loss of biodiversity (NNL) or similar are met in practice. This is complicated in marine systems where ecological predictions are commonly highly uncertain, knowledge of ecological restoration is low and administrative governance is complex. Drawing on a case study of marine biodiversity offsetting in Australia, this paper shows how these uncertainties pose practical challenges for both producers and consumers of marine biodiversity offsets, needing to progress with decision-making while meeting increasing societal pressure for demonstrable NNL. These competing needs are met through the centrality of an auditable decision-making process that contributes to establishing an organisation's social licence to operate. The need for auditability drives the use of an imprecise measure of NNL through financial equivalency and the use of strategic offsetting projects. The coarse-grained interpretation of biodiversity offsetting best practice reduces the risks posed by explicit acknowledgement of biodiversity loss, offset failure or prohibitively large offset liabilities. Strategic relationship management across government, industry, academia and non-governmental organisations has raised the profile of biodiversity and its importance, but whether the auditing process has delivered on environmental protection is an open question. What is ‘good enough’ to meet governance standards may have become the over-riding goal. We conclude by acknowledging that the seemingly unattainable yet expected aim of NNL for marine systems prioritises auditability above discussions of ‘acceptable’ risk