Towards Smart Hybrid Fuzzing for Smart Contracts

Smart contracts are Turing-complete programs that are executed across a blockchain network. Unlike traditional programs, once deployed they cannot be modified. As smart contracts become more popular and carry more value, they become more of an interesting target for attackers. In recent years, smart contracts suffered major exploits, costing millions of dollars, due to programming errors. As a result, a variety of tools for detecting bugs has been proposed. However, majority of these tools often yield many false positives due to over-approximation or poor code coverage due to complex path constraints. Fuzzing or fuzz testing is a popular and effective software testing technique. However, traditional fuzzers tend to be more effective towards finding shallow bugs and less effective in finding bugs that lie deeper in the execution. In this work, we present CONFUZZIUS, a hybrid fuzzer that combines evolutionary fuzzing with constraint solving in order to execute more code and find more bugs in smart contracts. Evolutionary fuzzing is used to exercise shallow parts of a smart contract, while constraint solving is used to generate inputs which satisfy complex conditions that prevent the evolutionary fuzzing from exploring deeper paths. Moreover, we use data dependency analysis to efficiently generate sequences of transactions, that create specific contract states in which bugs may be hidden. We evaluate the effectiveness of our fuzzing strategy, by comparing CONFUZZIUS with state-of-the-art symbolic execution tools and fuzzers. Our evaluation shows that our hybrid fuzzing approach produces significantly better results than state-of-the-art symbolic execution tools and fuzzers

Solutions for Impact Investors: From Strategy to Implementation

In writing this monograph, our main goal is to provide impact investors with tools to tighten the link between their investment decisions and impact creation. Our intent is threefold: to attract more capital to impact investing; to assist impact investors as they move from organizational change to executing and refining their impact investment decision-making process; and to narrow the gap within foundations between program professionals and investment professionals thereby contributing to a mutual understanding and implementation of a portfolio approach to impact investing.Additionally, we intend to help break down the barriers making it difficult to identify opportunities in impact investing. To this end, we provide examples throughout the monograph and at www.rockpa.org/impactinvesting of impact investment opportunities in most major asset classes.While we understand the important role that impact investors can play in providing financial capital, we also want to acknowledge the wide range of non-financial resources needed to address the world's problems. Our intent with this monograph is not to provide a comprehensive list of investments across asset classes nor any type of investment advice with regard to the selected profiles. We strongly encourage the reader to conduct their own assessment and evaluation for risk and suitability before considering any investment

Economic resilience : including a case study of the global transition network

This paper explores the dynamic properties of organisms and ecosystems that make them so resilient and capable of adapting to changing circumstances, allowing them to maintain an overall condition of coherence, wholeness and health while living in balance within the resources of the planet. Key principles of resilient ecological systems are explored including: self-regulation; positive and negative feedback; diversity; scale and context; cooperation; emergence and novelty; and ecological tipping points. In contrast, market based economic systems can produce unstable growth with unintended destruction of cultural and species diversity and homogenisation of global life-styles. The paper re-examines fundamental economic principles using insights from biological evolution and ecosystem dynamics to establish a foundation for more resilient economies. This involves experimenting with different models in different communities to find patterns of sustainable production and exchange appropriate to local regions. Fundamental steps in this direction include the emergence of self-organising local communities based on creative experimentation, re-localisation of core sectors of the economy (food, energy, health and education), evolution of local currencies and banking practices that support local enterprise and investment in green technologies, stimulation of decentralised renewable energy networks and economic reform aligned with ecological principles. The Transition Network provides a case study of an international community based movement that has been experimenting with putting some of these principles into practice at the local level. The aim of the Transition Network is to support community led responses to peak oil and climate change, building resilience and well-being. The concept of ecological resilience and its application to local economy is hard wired into the values and emerging structure of the network of transition communities across the globe. The movement started in the UK in 2005 and there are now over 1000 Transition initiatives spanning 34 countries across the world. Many attribute the success and phenomenal growth of the Transition Network to its emerging holographic structure that mimics cell growth within living organisms. Growing a more resilient food system in the face of the twin challenges of natural resource scarcity and climate change is central to the Transition movement. A set of principles for a post carbon resilient food economy in the UK are offered. These include an 80% cut in carbon emission in the food sector by 2050, agricultural diversification, prioritization of farming methods that establish and enhance carbon sinks, phasing out of dependence on fossil fuels in food growing, processing and distribution, promoting access to nutritious and affordable food, as well as promoting greater access to land for growing food in urban and peri-urban areas. Practical examples of Transition related projects in the food sector are presented across the following themes: access to land, low carbon production methods, food distribution systems, health and community gardens and orchards, and collaborative ownership models

Obvious: a meta-toolkit to encapsulate information visualization toolkits. One toolkit to bind them all

This article describes “Obvious”: a meta-toolkit that abstracts and encapsulates information visualization toolkits implemented in the Java language. It intends to unify their use and postpone the choice of which concrete toolkit(s) to use later-on in the development of visual analytics applications. We also report on the lessons we have learned when wrapping popular toolkits with Obvious, namely Prefuse, the InfoVis Toolkit, partly Improvise, JUNG and other data management libraries. We show several examples on the uses of Obvious, how the different toolkits can be combined, for instance sharing their data models. We also show how Weka and RapidMiner, two popular machine-learning toolkits, have been wrapped with Obvious and can be used directly with all the other wrapped toolkits. We expect Obvious to start a co-evolution process: Obvious is meant to evolve when more components of Information Visualization systems will become consensual. It is also designed to help information visualization systems adhere to the best practices to provide a higher level of interoperability and leverage the domain of visual analytics

Visual analytics for supply network management: system design and evaluation

We propose a visual analytic system to augment and enhance decision-making processes of supply chain managers. Several design requirements drive the development of our integrated architecture and lead to three primary capabilities of our system prototype. First, a visual analytic system must integrate various relevant views and perspectives that highlight different structural aspects of a supply network. Second, the system must deliver required information on-demand and update the visual representation via user-initiated interactions. Third, the system must provide both descriptive and predictive analytic functions for managers to gain contingency intelligence. Based on these capabilities we implement an interactive web-based visual analytic system. Our system enables managers to interactively apply visual encodings based on different node and edge attributes to facilitate mental map matching between abstract attributes and visual elements. Grounded in cognitive fit theory, we demonstrate that an interactive visual system that dynamically adjusts visual representations to the decision environment can significantly enhance decision-making processes in a supply network setting. We conduct multi-stage evaluation sessions with prototypical users that collectively confirm the value of our system. Our results indicate a positive reaction to our system. We conclude with implications and future research opportunities.The authors would like to thank the participants of the 2015 Businessvis Workshop at IEEE VIS, Prof. Benoit Montreuil, and Dr. Driss Hakimi for their valuable feedback on an earlier version of the software; Prof. Manpreet Hora for assisting with and Georgia Tech graduate students for participating in the evaluation sessions; and the two anonymous reviewers for their detailed comments and suggestions. The study was in part supported by the Tennenbaum Institute at Georgia Tech Award # K9305. (K9305 - Tennenbaum Institute at Georgia Tech Award)Accepted manuscrip

Measuring the Delivery Costs of Prepurchase Homeownership Education and Counseling

In order to understand the roles that public policy and the business and consumer sectors play in paying for homeownership education and counseling, the costs, benefits and beneficiaries of the education and training must be fully accounted for. This paper estimates the total costs of delivering homeownership education and counseling and discusses proven and implied benefits to stakeholders. Based on one set of assumptions, and depending on the level of activities offered, homeownership education and counseling costs range from $500 to$1,500. Empirical and anecdotal evidence suggest that homeownership education and counseling offer important benefits to borrowers, lenders, real estate professionals and communities. Many nonprofit organizations providing such services, however, remain underfunded. Providers, financial institutions and policy makers must increase their knowledge of what works, what costs are incurred, who benefits, and what value is created by homeownership education and counseling activities in order to develop a sustainable delivery system.This paper uses information from NeighborWorks organizations that offer homeownership education and counseling programs as illustration of the cost structure of the homeownership education and counseling industry. Part 2 provides background information on the homeownership education and counseling industry. Part 3 explains the methodology and assumptions used for this analysis. Part 4 reviews cost accounting and presents a framework for the cost analysis. Part 5 discusses the value proposition for homeownership education and counseling while Part 6 offers conclusions and implications

Monitor Sustainable Municipalities Report 2019 Key topic Circular Economy. Bertelsmann Stiftung Study 4 November 2019

At first sight, the concept for a recycling economy appears to be just the latest trend in the field of urban development, but in fact conversion to circular value creation also contains numerous oppor-tunities for the creation of long-term sustainable economic, social and environmental benefits for local communities. We have therefore chosen to look at this topic in this, our fourth, Monitor Report. Recycling Economy, Circular Value Creation and Cradle To Cradle are three concepts which – alt-hough each has a different main focus – basically all describe the same paradigm shift: away from a classic linear economy (“Take, Make, Use, Dispose”) towards a model based on restoration and regeneration. The recycling economy principle is actually anchored in the United Nations’ 17 Sustainable Devel-opment Goals, or SDGs. Goal 12 calls for sustainable consumption and sustainable production patterns. The recycling economy is also associated with a number of other sustainability goals, as it makes a significant contribution to their achievement. We are convinced that it is worth considering the applicability of the concept to local communities in Germany. What does transferring the recycling economy principle to local communities entail? How can towns be converted into “Recycling Cities”? Where are the obstacles and what potential is there? This Monitor Report is a first – it is the first bilingual version. With the kind permission of the Collab-orating Centre for Sustainable Consumption and Production (CSCP) in Wuppertal, we have issued their “Circular Economy Guidebook for Cities” in the original English with a German translation. We hope that, by looking at the bigger picture, we will also generate the impulse to consider how the topic can be adopted in (European) towns and cities, and what the resulting benefits could be. We are fully aware that a one-to-one transfer will not work. “One size fits all” does not apply to local communities. Although something that makes sense in Amsterdam, Copenhagen or Oslo may not necessarily work in towns, districts and local communities in Germany, it is definitely worth looking at how things are done in other countries. I would sincerely like to thank everyone who contributed to the creation of this Report, and especially the CSCP for its trust and invaluable cooperation. We hope you enjoy reading the Report, and look forward as always to your feedback and suggestions