192 research outputs found

    A Rule of Persons, Not Machines: The Limits of Legal Automation

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    Close to the metal: Towards a material political economy of the epistemology of computation

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    This paper investigates the role of the materiality of computation in two domains: blockchain technologies and artificial intelligence (AI). Although historically designed as parallel computing accelerators for image rendering and videogames, graphics processing units (GPUs) have been instrumental in the explosion of both cryptoasset mining and machine learning models. The political economy associated with video games and Bitcoin and Ethereum mining provided a staggering growth in performance and energy efficiency and this, in turn, fostered a change in the epistemological understanding of AI: from rules-based or symbolic AI towards the matrix multiplications underpinning connectionism, machine learning and neural nets. Combining a material political economy of markets with a material epistemology of science, the article shows that there is no clear-cut division between software and hardware, between instructions and tools, and between frameworks of thought and the material and economic conditions of possibility of thought itself. As the microchip shortage and the growing geopolitical relevance of the hardware and semiconductor supply chain come to the fore, the paper invites social scientists to engage more closely with the materialities and hardware architectures of ‘virtual’ algorithms and software

    The Miner's Dilemma

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    An open distributed system can be secured by requiring participants to present proof of work and rewarding them for participation. The Bitcoin digital currency introduced this mechanism, which is adopted by almost all contemporary digital currencies and related services. A natural process leads participants of such systems to form pools, where members aggregate their power and share the rewards. Experience with Bitcoin shows that the largest pools are often open, allowing anyone to join. It has long been known that a member can sabotage an open pool by seemingly joining it but never sharing its proofs of work. The pool shares its revenue with the attacker, and so each of its participants earns less. We define and analyze a game where pools use some of their participants to infiltrate other pools and perform such an attack. With any number of pools, no-pool-attacks is not a Nash equilibrium. With two pools, or any number of identical pools, there exists an equilibrium that constitutes a tragedy of the commons where the pools attack one another and all earn less than they would have if none had attacked. For two pools, the decision whether or not to attack is the miner's dilemma, an instance of the iterative prisoner's dilemma. The game is played daily by the active Bitcoin pools, which apparently choose not to attack. If this balance breaks, the revenue of open pools might diminish, making them unattractive to participants

    A study of user experiences and network analysis on anonymity and traceability of bitcoin transactions

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    This paper investigates the anonymity of bitcoin transactions and significance of awareness of the technology by bitcoin users, alongside their experiences in tracing transactions. Bitcoin enables users to carry out transactions anonymously with the virtual currency without unveiling where the real-world source of the income has come from. These transactions may occur without revealing locations or any personal identifiable information of the person who is sending or receiving bitcoins. While there are existing surveys which test bitcoin users’ awareness of the technology, they do not focus on bitcoin users’ own experience using the technology in terms of tracing transactions and use of anti-forensic tools to increase the level of anonymity. This paper reports significance of users’ opinions on traceability and anonymity of bitcoin transactions and compares users’ viewpoints collected from a survey with experimental findings observed using network analysis tools

    The Bitcoin Brain Drain: Examining the Use and Abuse of Bitcoin Brain Wallets

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    In the cryptocurrency Bitcoin, users can deterministically derive the private keys used for transmitting money from a password. Such “brain wallets” are appealing because they free users from storing their private keys on untrusted computers. Unfortunately, they also enable attackers to conduct unlimited offline password guessing. In this paper, we report on the first large-scale measurement of the use of brain wallets in Bitcoin. Using a wide range of word lists, we evaluated around 300 billion passwords. Surprisingly, after excluding activities by researchers, we identified just 884 brain wallets worth around $100K in use from September 2011 to August 2015. We find that all but 21 wallets were drained, usually within 24 h but often within minutes. We find that around a dozen “drainers” are competing to liquidate brain wallets as soon as they are funded. We find no evidence that users of brain wallets loaded with more bitcoin select stronger passwords, but we do find that brain wallets with weaker passwords are cracked more quickly

    An infrastructure service recommendation system for cloud applications with real-time QoS requirement constraints

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    The proliferation of cloud computing has revolutionized the hosting and delivery of Internet-based application services. However, with the constant launch of new cloud services and capabilities almost every month by both big (e.g., Amazon Web Service and Microsoft Azure) and small companies (e.g., Rackspace and Ninefold), decision makers (e.g., application developers and chief information officers) are likely to be overwhelmed by choices available. The decision-making problem is further complicated due to heterogeneous service configurations and application provisioning QoS constraints. To address this hard challenge, in our previous work, we developed a semiautomated, extensible, and ontology-based approach to infrastructure service discovery and selection only based on design-time constraints (e.g., the renting cost, the data center location, the service feature, etc.). In this paper, we extend our approach to include the real-time (run-time) QoS (the end-to-end message latency and the end-to-end message throughput) in the decision-making process. The hosting of next-generation applications in the domain of online interactive gaming, large-scale sensor analytics, and real-time mobile applications on cloud services necessitates the optimization of such real-time QoS constraints for meeting service-level agreements. To this end, we present a real-time QoS-aware multicriteria decision-making technique that builds over the well-known analytic hierarchy process method. The proposed technique is applicable to selecting Infrastructure as a Service (IaaS) cloud offers, and it allows users to define multiple design-time and real-time QoS constraints or requirements. These requirements are then matched against our knowledge base to compute the possible best fit combinations of cloud services at the IaaS layer. We conducted extensive experiments to prove the feasibility of our approach

    Cryptocurrencies and Bitcoin: Charting the Research Landscape

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    This systematic literature review examines cryptocurrencies (CCs) and Bitcoin. Because cryptocurrency research has not gained much attention from Information Systems (IS) researchers and needs a more vivid discussion, this review summarizes the main concepts of 42 papers and aligns them to IS Research. Although, cryptocurrency research has not reached IS mainstream yet, there is massive potential for multifaceted research ranging from protocol development to designing alternative digital currency schemes. Cryptocurrencies entail a core digital artifact and present a rich phenomenon based on the intertwining of technological artifacts and social contexts. We argue that cryptocurrencies are an alternative payment method that may replace intermediaries with cryptographic methods and should be embedded in the research areas of SIGeBIZ and SIGSEC. At the end of this literature review, we discuss some open research gaps like new business models based on cryptocurrencies or the influence of culture on cryptocurrencies and Bitcoin
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