Blockchain Papers

Fergus Dall, Gabrielle De Micheli, Thomas Eisenbarth, Daniel Genkin · 7 authors

Intel Software Guard Extensions (SGX) allows users to perform secure computation on platforms that run untrusted software. To validate that the computation is correctly initialized and that it executes on trusted hardware, SGX supports attestation providers that can vouch for the user’s computation. Communication with these attestation providers is based on the Extended Privacy ID (EPID) protocol, which not only validates the computation but is also designed to maintain the user’s privacy. In particular, EPID is designed to ensure that the attestation provider is unable to identify the host on which the computation executes. In this work we investigate the security of the Intel implementation of the EPID protocol. We identify an implementation weakness that leaks information via a cache side channel. We show that a malicious attestation provider can use the leaked information to break the unlinkability guarantees of EPID. We analyze the leaked information using a lattice-based approach for solving the hidden number problem, which we adapt to the zero-knowledge proof in the EPID scheme, extending prior attacks on signature schemes.

Seán Lynch

OpenLitterMap rewards users with Littercoin for producing open data on litter. Open data on the geospatial characteristics of litter provide means of invoking and evaluating responses to plastic pollution. OpenLitterMap currently works as a web app on all devices with native mobile apps in development. The stack includes the integration of the Laravel PHP Framework on the backend; Vue for frontend reactivity; NativeScript-Vue for mobile apps; Bulma for CSS; Leaflet for web-mapping; Turf.js for geospatial analysis; the Ethereum Blockchain for tokenization; Stripe; ChartJS; AWS; and more. Anywhere from a single cigarette butt to the contents of an entire beach or street clean can be logged in a single geotagged photo. Alternatively, a simple index may be used if litter is incalculable. The open data includes an increasing 100+ pre-defined types of litter; 20+ corporate brands; verification status; coordinates; timestamp; phone model; the latest OpenStreetMap address at each location; and the litter presence as a Boolean. To date, 100% of all submitted data (~ 8200 photos, ~ 28,000 litter from over 150 contributors) has been manually verified which is being used to develop machine learning algorithms.

Stephen Armstrong

Blockchain recording of digital transactions could have many healthcare applications—from patient records to tracing pills—reports Stephen Armstrong , but is its potential overhyped? The cryptocurrency boom may be over, according to recent reports,1 but interest in its underlying technology, the blockchain, is far from it. Digital health experts are starting to wonder if blockchain could solve NHS data problems, and the UK’s first trial of blockchain technology to create and support electronic health records will begin in July at a southwest London general practice group (box 1).8 Box 1 ### Blockchain examples in health #### Countering counterfeits “The blockchain provides a granular trail of a product’s journey,” explains Peter Bryant, chief operating officer of UK based global drug tracking system FarmaTrust. With the Drug Supply Chain Security Act in the US rolling out between 2015 and 2023,2 and the equivalent Falsified Medicines Directive in the EU coming into force next spring,3 all pharmaceutical products will require a label with a unique serial number, name, lot number, batch number, and expiry date. FarmaTrust is talking to 13 manufacturers as well as the Mongolian government to offer a blockchain tracking system that can link with existing databases. The company is also working with medicinal poppy and marijuana growers and the government in Thailand to ensure that products are traceable and the farmers are taxed on profits. #### Patient records Technology company Medicalchain is partnering with southwest London general practice group, The Groves, in the UK’s first trial of blockchain to create and support electronic health records.4 It offers registered patients a free digital wallet to hold and manage access to their health records. The platform includes a cryptocurrency—Medicalchain’s MedTokens—to encourage patients to participate, which they can use as private patients to pay for telemedicine services. Elsewhere, MIT research project MedRec is trialling a health records system that leaves patient … RETURN TO TEXT

Edgar González Fernández, Guillermo Morales-Luna, Feliú Sagols Troncoso

Zero-Knowledge Proofs ZKP provide a reliable option to verify that a claim is true without giving detailed information other than the answer. A classical example is provided by the ZKP based in the Graph Isomorphism problem (GI), where a prover must convince the verifier that he knows an isomorphism between two isomorphic graphs without publishing the bijection. We design a novel ZKP exploiting the NP-hard problem of finding the algebraic ideal of a multivariate polynomial set, and consequently resistant to quantum computer attacks. Since this polynomial set is obtained considering instances of GI, we guarantee that the protocol is at least as secure as the GI based protocol.

George Kappos, Haaroon Yousaf, Mary Maller, Sarah Meiklejohn

Among the now numerous alternative cryptocurrencies derived from Bitcoin, Zcash is often touted as the one with the strongest anonymity guarantees, due to its basis in well-regarded cryptographic research. In this paper, we examine the extent to which anonymity is achieved in the deployed version of Zcash. We investigate all facets of anonymity in Zcash's transactions, ranging from its transparent transactions to the interactions with and within its main privacy feature, a shielded pool that acts as the anonymity set for users wishing to spend coins privately. We conclude that while it is possible to use Zcash in a private way, it is also possible to shrink its anonymity set considerably by developing simple heuristics based on identifiable patterns of usage.

Benedikt Seiler, Daniel Seiler

Die Autoren gehen der Frage nach, ob Kryptowährungen als Sachen im Sinne des ZGB aufgefasst und daran namentlich Eigentumsrechte begründet werden können. Dabei werden zunächst technische Grundlagen der sog. Blockchain-Technologie und der drei nach Markkapitalisierung grössten Kryptowährungen Bitcoin (BTC), Ethereum (Ether, ETH) und Ripple (XRP) dargestellt. Sodann wird untersucht, ob diese Kryptowährungen die Eigenschaften erfüllen, welche für die Qualifikation eines Objektes als Sache im Sinne des ZGB vorliegen müssen, und welches die Folgen einer solchen Qualifikation sind. Im Sinne einer modernen Auslegung des Sachbegriffs schliessen sich die Autoren der Auffassung an, wonach Kryptowährungen grundsätzlich als Sache und damit als Gegenstand des Eigentums zu behandeln sind.

Gowri Ramachandran, Bhaskar Krishnamachari

Blockchain technology has been transforming the financial industry and has created a new crypto-economy in the last decade. The foundational concepts such as decentralized trust and distributed ledger are promising for distributed, and large-scale Internet of Things (IoT) applications. However, the applications of Blockchain beyond cryptocurrencies in this domain are few and far between because of the lack of understanding and inherent architectural challenges. In this paper, we describe the opportunities for applications of blockchain for the IoT and examine the challenges involved in architecting Blockchain-based IoT applications.

Dipti Pawade, Sagar Jape, R. Balasubramanian, Mihir Kulkarni · 5 authors

In the financial systems of the modern era, trust has always been a missing entity; concentrations of power and trust have given birth to numerous breakdowns. To resolve the problems at this end, the paper attempts for a solution using Blockchains, a data structure that allows for the creation of cryptically secured distributed tamperproof ledgers. The paper discusses the data structure and further disserts on the case study in consideration.

Wenbo Wang, Dinh Thai Hoang, Peizhao Hu, Zehui Xiong · 8 authors

The past decade has witnessed the rapid evolution in blockchain technologies, which has attracted tremendous interests from both the research communities and industries. The blockchain network was originated from the Internet financial sector as a decentralized, immutable ledger system for transactional data ordering. Nowadays, it is envisioned as a powerful backbone/framework for decentralized data processing and data-driven self-organization in flat, open-access networks. In particular, the plausible characteristics of decentralization, immutability, and self-organization are primarily owing to the unique decentralized consensus mechanisms introduced by blockchain networks. This survey is motivated by the lack of a comprehensive literature review on the development of decentralized consensus mechanisms in blockchain networks. In this paper, we provide a systematic vision of the organization of blockchain networks. By emphasizing the unique characteristics of decentralized consensus in blockchain networks, our in-depth review of the state-of-the-art consensus protocols is focused on both the perspective of distributed consensus system design and the perspective of incentive mechanism design. From a game-theoretic point of view, we also provide a thorough review of the strategy adopted for self-organization by the individual nodes in the blockchain backbone networks. Consequently, we provide a comprehensive survey of the emerging applications of blockchain networks in a broad area of telecommunication. We highlight our special interest in how the consensus mechanisms impact these applications. Finally, we discuss several open issues in the protocol design for blockchain consensus and the related potential research directions.

Wenbo Wang, Dinh Thai Hoang, Zehui Xiong, Dusit Niyato · 7 authors

The past decade has witnessed the rapid evolution in blockchain technologies, which has attracted tremendous interests from both the research communities and the industry. The blockchain network was originated in the Internet finical sector as a decentralized, immutable ledger system for transactional data ordering. Nowadays, it is envisioned as a powerful backbone/framework for decentralized data processing and data-driven self-organization in flat, open-access networks. In particular, the plausible characteristics of decentralization, immutability and self-organization are primarily owing to the unique decentralized consensus mechanisms introduced by blockchain networks. This survey is motivated by the lack of a comprehensive literature review on the development of decentralized consensus mechanisms in blockchain networks. In this survey, we provide a systematic vision of the organization of blockchain networks. By emphasizing the unique characteristics of incentivized consensus in blockchain networks, our in-depth review of the state-of-the-art consensus protocols is focused on both the perspective of distributed consensus system design and the perspective of incentive mechanism design. From a game-theoretic point of view, we also provide a thorough review on the strategy adoption for self-organization by the individual nodes in the blockchain backbone networks. Consequently, we provide a comprehensive survey on the emerging applications of the blockchain networks in a wide range of areas. We highlight our special interest in how the consensus mechanisms impact these applications. Finally, we discuss several open issues in the protocol design for blockchain consensus and the related potential research directions.

Unknown author

This paper proposes a novel adaptation of blockchain technology to information exchanges among vehicles traveling in a platoon. The aim is to protect platoon member privacy and security while providing a rapid sharing of telemetry data. We have identified key protocols for a distributed cryptographic authentication among vehicles in transit within a platoon. This work heralds consideration of cyber-attack types on platoons and our proposed remedies.

Yacov Manevich, Artem Barger, Yoav Tock

Hyperledger Fabric (HLF) is a modular and extensible permissioned blockchain platform released to open-source and hosted by the Linux Foundation. The platform's design exhibits principles required by enterprise grade business applications like supply-chains, financial transactions, asset management, food safety, and many more. For that end HLF introduces several innovations, two of which are smart contracts in general purpose languages (\emph{chaincode} in HLF), and flexible endorsement policies, which govern whether a transaction is considered valid. Typical blockchain applications are comprised of two tiers: the first tier focuses on the modelling of the data schema and embedding of business rules into the blockchain by means of smart contracts (\emph{chaincode}) and endorsment policies; and the second tier uses the SDK (Software Development Kit) provided by HLF to implement client side application logic. However there is a gap between the two tiers that hinders the rapid adoption of changes in the chaincode and endorsement policies within the client SDK. Currently, the chaincode location and endorsement policies are statically configured into the client SDK. This limits the reliability and availability of the client in the event of changes in the platform, and makes the platform more difficult to use. In this work we address and bridge the gap by describing the design and implementation of \emph{Service Discovery}. \emph{Service Discovery} provides APIs which allow dynamic discovery of the configuration required for the client SDK to interact with the platform, alleviating the client from the burden of maintaining it. This enables the client to rapidly adapt to changes in the platform, thus significantly improving the reliability of the application layer. It also makes the HLF platform more consumable, simplifying the job of creating blockchain applications.

David Billard

When digital evidence is presented in front of a court of law, it is seldom associated with a scientific evaluation of its relevance, or significance. When experts are challenged about the validity of the digital evidence, the general answer is "yes, to a reasonable degree of scientific certainty". Which means all and nothing at the same time, since no scientific metric is volunteered. In this paper we aim at providing courts of law with weighted digital evidence. Each digital evidence is assigned with a confidence rating that eventually helps juries and magistrates in their endeavor. This paper presents a novel methodology in order to:

Sarmadullah Khan, Rafiullah Khan

Recently, advancements in energy distribution models have fulfilled the needs of microgrids in finding a suitable energy distribution model between producer and consumer without the need of central controlling authority. Most of the energy distribution model deals with energy transactions and losses without considering the security aspects such as information tampering. The transaction data could be accessible online to keep track of the energy distribution between the consumer and producer (e.g., online payment records and supplier profiles). However this data is prone to modification and misuse if a consumer moves from one producer to other. Blockchain is considered to be one solution to allow users to exchange energy related data and keep track of it without exposing it to modification. In this paper, electrical transactions embedded in blockchain are validated using the signatures of multiple producers based on their assigned attributes. These signatures are verified and endorsed by the consumers satisfying those attributes without revealing any information. The public and private keys for these consumers are generated by the producers and endorsement procedure using these keys ensures that these consumers are authorized. This approach does not need any central authority. To resist against collision attacks, producers are given a secret pseudorandom function seed. The comparative analysis shows the efficiency of proposed approach over the existing ones.

F. Juárez Hernández, Rafael Hernández

In this article, the authors discuss the VAT treatment of sales and transfers of Bitcoin carried out in Mexico. For this purpose, they analyse the current state of Mexican law, but also review the applicable VAT regime in jurisdictions around the world, such as in Japan, Spain, Switzerland and the European Union. The authors then provide an overview of recently enacted legislation in Mexico and its foreseeable impact on the VAT treatment of Bitcoin.

Ahmad Firdaus, Nor Badrul Anuar, Mohd Faizal Ab Razak, Mohamed Hashem · 6 authors

No abstract is available for this record.

Adam Watt

‘[N]ous ne cessons d’ajouter à la Recherche (comme Proust le faisait sur ses manuscrits)’, writes Roland Barthes in 1979, ‘nous ne cessons de l’écrire.’1 In the very nearly forty years since these remarks were made, critics, scholars, filmmakers, creative writers, and others, have indeed continued the process of addition and continuation that Barthes identifies.2 It may be, in fact, that we live in a golden age of Proust scholarship. A diplomatic edition of Proust’s Cahiers is underway and work is progressing towards an accessible digital edition of the correspondence; the publication of a new scholarly edition of À la recherche du temps perdu has begun.3 Whilst well-worn paths are still trodden, original, adventurous, and rigorous research continues to illuminate the field.4 Christopher Prendergast’s scintillating Mirages and Mad Beliefs, for example, dismantles critical commonplaces, drawing attention to an intermittent voice, ‘a sotto voce emanation from the margins and often audible only in the tones of ironic indirection’.5 In attuning our ear to this sceptical voice, Prendergast challenges the primacy of redemptive aesthetics that has long been taken for granted in Proust criticism. At the same time, we find recurring reference to Proust in Terence Cave’s Thinking with Literature — an indication of what another critic has called Proust’s plasticity: his ability to be many things to many readers.6 In preparing an état présent on Proust, Proustian questions soon arise about how far back one should reach into the past; about the extent to which things one might assume to be constant and unchanging do in fact continue to evolve and take on new shapes or resonances. Faced with the vast scale of critical and creative responses to Proust it seems judicious to focus principally on work produced since 2013. This is a relatively recent cut-off, but it is made for compelling reasons. The year 2013 marked the centenary of the publication of Du côté de chez Swann, the first volume of À la recherche du temps perdu, and as such there was a considerable spike in scholarly publications that year.7 Among these was the landmark edited volume Marcel Proust in Context, the final section of which, ‘Critical Reception’, consists of six chapters spanning topics from the critical reception of À la recherche during Proust’s lifetime to critical responses, translations, and adaptations up to 2012.8 The current état présent, therefore, picks up from this point and identifies six areas for consideration: correspondence, biography, and genetic criticism; philosophy; the arts; intertextual, contextual, and thematic studies; modernism; and creative responses. Before beginning, it is worth noting a trio of recent essays that merit inclusion on reading lists for those broaching Proust for the first time. Marion Schmid’s wide-ranging chapter ‘Marcel Proust (1871–1922): A Modernist Novel of Time’ attends accessibly to a variety of features of À la recherche and is especially clear about the novel’s double internal focalization.9 Also using the question of time to structure a wonderfully lucid essay, Michael Lucey provides an excellent survey of Proust’s stylistic, formal, and thematic innovations in his chapter ‘Becoming Proust in Time’.10 Lastly, Edward Hughes’s characteristically insightful chapter on ‘The Renewal of Narrative in the Wake of Proust’ casts a comparative gaze across narrative practice in French fiction in the middle to end of the twentieth century, giving a useful account of Proust’s legacy to later writers.11 In Proust among the Stars, Malcolm Bowie seeks to steer attention towards what he calls the ‘dazzling procession of Proust’s paragraphs’ and away from the fascinating yet ultimately ‘thin thread of Proust’s biography’.12 That thread, however, is a resilient one with considerable allure. William C. Carter’s authoritative biography, first published in 2000, was reprinted with corrections and a new preface for the Swann centenary in 2013.13 Jean-Yves Tadié, author of the standard French life of Proust, has supplemented his contribution with Proust et ses amis, published in 2010, and Le Cercle de Marcel Proust, a two-volume edited collection of essays on Proust’s acquaintances: together these three volumes substantively enhance our appreciation of the relationships (both enduring and fleeting) Proust maintained as his novel took shape.14 Despite the crowded field, a major new biography was published in French in 2015, Jérôme Picon’s Marcel Proust: une vie à s’écrire.15 This is an extensive account, drawing above all on Proust’s correspondence, including discoveries of the last two decades and, in particular, the revised dating of certain letters included in the 2004 selection edited by Françoise Leriche.16 Picon’s book is a work of considerable scholarship, but lacks the narrative finesse of the accounts of Carter or Tadié. Two shorter lives also appeared just before Picon’s: my own Marcel Proust in Reaktion Books’ ‘Critical Lives’ series, which seeks to explore how Proust came to write À la recherche and to plot the parallel tracks of his declining health and his ever-expanding novel; and Benjamin Taylor’s Proust: The Search, which appears in Yale’s ‘Jewish Lives’ series.17 More recently still, Évelyne Bloch-Dano, biographer of Proust’s mother, has published a partial biography focusing on Proust’s childhood.18 In parallel, various periods of his life have received renewed attention with the publication of newly discovered correspondence. Michel Schneider’s L’Auteur, l’autre: Proust et son double (2014) is a book-length study eked out of previously unseen but ultimately rather thin manuscript materials: a handful of letters and an essay of just over four pages in length, ‘L’Esthétique de Marcel Proust’, written by Proust in 1921. The essay, Schneider argues, ‘est un document passionnant pour comprendre le regard que Proust porte sur son œuvre à la toute fin de sa vie’.19 Schneider’s book contains insights of a psycho-bio-critical nature, but the ‘auteur’/‘autre’ dichotomy becomes somewhat strained over very nearly three hundred pages. The Lettres au duc de Valentinois, dating from 1920, were published in 2016, shortly after the high-profile publication of the Lettres à sa voisine, a collection of twenty-three brief missives sent by Proust to his neighbour, the wife of an American dentist in boulevard Haussmann, between 1908–09 and 1919.20 In addition to these discoveries, the scholarly accessibility of Proust’s correspondence will soon be greatly boosted by a collaborative project that is making digitally available some two hundred of Proust’s letters relating to the First World War, with an anticipated launch date of 11 November 2018.21 At times in Proust’s letters the initial shapes of ideas or scenarios are tested out, weighed up. Proust’s multifaceted, iterative processes of drafting, expanding, and refining his material continue to receive a great deal of attention, above all from the scholars associated with the ‘Équipe Proust’ based at the Institut des textes et manuscrits modernes (ITEM) in Paris, directed by Nathalie Mauriac Dyer. A flavour of the breadth and insights of recent genetic criticism is richly in evidence in the special number of the journal Genesis edited by Mauriac Dyer for the Swann centenary: Proust, 1913, the entirety of which is free to access online.22 Much of the material discussed here pertains to the major project of the ‘Équipe Proust’, the ongoing preparation and publication of a complete edition of the Cahiers 1 à 75 de la Bibliothèque nationale de France.23 The annually published journal of the ‘Équipe’, the Bulletin d’informations proustiennes, edited by Mauriac Dyer, provides insights and sidelights on the work of the scholars associated with the team and the monthly seminars it runs (for the transcription of Proust’s cahiers as well as related academic papers and symposia).24 Although the high cost of the ongoing edition of Proust’s Cahiers makes its volumes inimical to most individual budgets, the full and cost-free digital accessibility, via the Gallica platform, of the Bibliothèque nationale’s ‘fonds Proust’, the manuscript cahiers, notebooks, loose pages, proof-copy, paste-ons, and so forth that are the central focus of the genetic endeavour, means that anyone with an internet connection can now access high-definition reproductions of the ink-and-paper origins of Proust’s novel.25 The intersections of Proust’s writings with philosophy have long preoccupied readers and critics. The publication in 2013 of Luc Fraisse’s L’Éclectisme philosophique de Marcel Proust, however, was a genuinely field-changing event.26 A number of influential studies appeared in the preceding years: in particular Joshua Landy’s Philosophy as Fiction, which sheds light on truth, perspective and (self-) deception, and Anne Simon’s Proust ou le réel retrouvé, which lucidly accounts for Proust’s handling of sensory experience.27 Shorter, though important, contributions have been made by Martin Hägglund’s pages on Proust in Dying for Time: Proust, Woolf, Nabokov, which reassess major questions of temporality and desire; by Erika Fülöp in her study of ‘identity and difference’ in À la recherche; and by Jessica Wiskus in the attention she pays to Proust’s phenomenology, through a comparative lens, in The Rhythm of Thought.28 Fraisse’s L’Éclectisme stands out, though, by dint of the sheer breadth and depth of the scholarship upon which it is built. Well over 1,200 pages in length, Fraisse’s study draws abundantly on those texts Proust is known to have read or been exposed to at the Lycée Condorcet, at the Sorbonne, and later in life, as well as those he is likely to have encountered or become acquainted with. Fraisse not only constructs an incremental picture of Proust’s philosophical apprenticeship and development (alongside familiar tutelary figures such as Alphonse Darlu, Paul Janet, Gabriel Séailles, and many, perhaps less familiar, others from his readings) and provides suggestive accounts of the philosophical sources or underpinnings of various scenes from À la recherche; he also provides a rich and discerning account of the philosophical and philosophically inflected reception of Proust’s work (by Proust’s contemporaries as well as critics and thinkers including Anne Henry, Gilles Deleuze, Roland Barthes, and Anne Simon). L’Éclectisme philosophique de Marcel Proust is an exceptional work of erudition that will remain a touchstone in the field for generations of scholars. Fraisse’s work combines intellectual history, reception studies, and textual criticism; a good many insights have been yielded by shorter publications contributing to one or other of these fields in the years since 2013. Jennifer Rushworth and Anna Elsner have fruitfully brought Jacques Derrida’s thought to bear on readings of Proust’s novel.29 Anne Simon’s Trafics de Proust, though less ambitious in scope than Fraisse, is every bit as accomplished in its handling and analysis of material. With perhaps a nod to Michel de Certeau, Simon modestly describes her sparkling central chapters as ‘quatre butinages différents’.30 From this foraging among the writings of Merleau-Ponty, Sartre, Deleuze, and Barthes emerges a Proust who is ‘un référent majeur de leur façon de s’envisager et d’envisager l’exercice de la pensée’.31 Over and again Simon demonstrates persuasively and with great critical sensitivity how Proust’s work becomes ‘une référence en puissance, à tous les niveaux — narratif, thématique, lexical ou rythmique’.32 Like philosophy — and like Proust’s novel — the arts are a house with many rooms, and this is reflected in the volume and diversity of material published in relation to Proust and the arts. The popular appeal of this domain is evinced by the recent re-issue, in paperback, of Eric Karpeles’s Paintings in Proust, whilst a more scholarly and, indeed, authoritative account of painting in Proust is found in Kazuyoshi Yoshikawa’s Proust et l’art pictural.33 Richly illustrative of the range of original responses Proust’s relations with the arts still provoke is the recent edited volume Proust and the Arts.34 Artists and topics are attended to here that one might expect in such a volume — Jean-Baptiste-Siméon Chardin, Gustave Moreau, John Ruskin, Vittore Carpaccio, Richard Wagner, photography — but also others that refresh and rejuvenate a field one might have thought quite saturated.35 There are essays relating to archaeological discovery; fashion; Proust’s own drawings; Émile Gallé’s work in glass; book art and illustration; acts of listening; and, remarkably and entertainingly, Proust and the Marx brothers. Additionally, readers will garner much from the similarly stimulating Proust et les arts décoratifs,36 and from the wide-ranging Proust and the Visual.37 Sophie Basch’s sumptuously illustrated Rastaquarium: Marcel Proust et le ‘modern style’ is a hugely impressive work of cultural-historical scholarship that adds yet greater nuance to our understanding of the layers of reference Proust built into his work and their polyvalence within it.38 Dance is a minor art in À la recherche and has received little attention until recently. Áine Larkin’s chapter on ‘Theatre and Dance’ in Marcel Proust in Context surveys the cultural-historical context and attends to the most important relevant scenes in the novel, whilst a recent article by Schmid explores resonances between the radical changes in dance in the early twentieth century and Proust’s writing of À la recherche.39 Francine Goujon has considered similar material, tracing Proust’s encounters with the ballets russes and the of of a likely based on in his and in the novel is Schmid’s excellent of Roland Proust, les du Schmid and new with their Proust at the de Proust, at hundred pages of has made a incremental contribution to the combines of Proust’s of and towards and of the of his novel, with analysis of adaptations of À la also attends to questions of and recently there has been a spike in critical in Proust’s relation to the art as a of the by of of Proust the of the in after the of de and in The a number au temps du un including an article by and his The and for a or two the over Proust in for the first have also been made in our understanding of the of photography in Proust’s Larkin’s Proust is a standard reference now and has been by a range of other out related and In to Additionally, through a of and a has the study of photography to the and of Proust, Barthes, and a also in years have a of to about the of in Proust’s A special of edited by Proust and for the in questions about and and the of all of as found in Proust’s work is also important to recent study Proust, and which that by how was to in time and in Proust’s time, one might a more to Proust’s away from readings of in Proust as an access to by and by Anne for the iterative of the as illustrative of the of the associated of which we find in Proust’s novel not just in scenes of The marked in focus and between study and Proust de la more the diversity of responses to the same of Proust’s the and is and in a volume of and reading in Proust’s his correspondence, and in the writing of Proust’s time. is an authoritative account of the and development of the scenes relating to in À la recherche and a contribution to Proust’s relations to the and critics of his time. Proust de la is an important that we still have much to from the study of and Proust’s correspondence as an initial to what he was reading or exposed and from the accessibility of the Gallica platform, may yet have discoveries to in relation to sources and so that may have to this or that or of scholars with a about or in or to Proust’s novel, du Proust et ses sources is an The volume by Fraisse written or in the between the early and 2010, and through essays on a range of from de and the de to contemporaries such as and Anna de and later including and recent Proust, and an important, in Proust to a of the relations between Proust and but also provides fascinating analysis of the reception and of Proust’s novel in how and scholars the of the novel as its of and the study of seeks in to what has called between a recent in Proust studies is the attention to the and between Proust’s writings and those of Proust is a yet œuvre and in particular, through a of and some has this The publication of de in a number of that the of Proust in to with his writing in the that and Proust, like others, the of scholarship has this and a range of in which the writing and thought with Proust’s of in and Proust is a and impressive work of comparative scholarship that that and are and of and practice have been exposed by The intersections of Proust and the first up in Richard research over forty years have been in a of an edited Proust et les that has renewed attention is the First World now have an excellent range of sources to to Proust and his novel within the context of the years to from of made to the of the novel to the of the to studies of Proust’s and during the is one of the that across the of the First World and the of the by the is encountered one to Proust’s in this since its is a critical with in the study of in French within the French Modernist studies, however, is a field a great deal of critical material, by scholars in or comparative A handful of studies have and are in scholarship on Proust, such as The of which contains a insightful chapter on and the in A recent work of finesse and critical is which Proust Nathalie and Much scholarship, however, not it on to the or of those on Proust, which is a since there is a good deal of in the it seems that relatively little Proust criticism — — is read by those who as scholars Proust example, in his recent of from to de a stimulating section on the of in the development of the aesthetics in Proust’s A compelling is made, but it have been and by reference to important, work by Jacques or by in Proust, and find similar in which is principally a study of and read with and through especially the writings of William A Proust’s writing on with the two though not original yet pays to work on Proust and philosophy the only critical to Proust that is is In recent major the has been rather insightful chapter on et and its to with and figures in the edited volume in his contribution to of the Modernist his chapter on and the French with to Proust, with his with in and with the that À la recherche is a work that ultimately one just how this Proust that essay, he is more the of another by in The of which provides a more account of Proust’s in the in over the full of his creative Lastly, it is via a of and life that attends to Proust as a and in his recent of pages relating to Proust do not previously about À la their in the as it on questions of and and and a to this French author as a in a the and that in to À la a but number of creative responses have the domain in recent as to and with À la recherche from Anne novel and others, which and to Proust in responses have also appeared that questions for research about shapes and for Anne The is at a critical to and relations in Proust’s novel and an of scholarly towards more extensive of is an of critical and thought the critical essay and the were related writes and, indeed, in Christopher yet more radical The Proust in and out as from to and responses may not be the of criticism but how we read and with À la recherche; also the fact of Proust’s and his as Anne Simon has ‘un à une de de ou

Juan M. Román-Belmonte, Hortensia De la Corte‐Rodríguez, E. Carlos Rodríguez‐Merchán

Although the best-known use of blockchain technology (BCT) is in the field of economics and cryptocurrencies in general, its usefulness is extending to other fields, including the biomedical field. The purpose of this article is to clarify the role that BCT can play in the field of medicine. We have performed a narrative review of the literature on BCT in general and on medicine in particular. The great advantage of BCT in the health arena is that it allows development of a stable and secure data set with which users can interact through transactions of various types. This environment allows the entry and operation of clinical data without compromising other sensitive data. Another important advantage of BCT is that the entire network is decentralized and is maintained by the users themselves; thus, there is no need to rely on organizations for storage. The Blockchain code is open source and can be used, modified and revised by its users. BCT literature is scarce so far. This article describes the basics of this technology and summarizes the various aspects in which BCT could change the paradigm of current medicine. The great potential of BCT, as well as its many applications in the field of health sciences, encompasses the fields of legal medicine, research, electronic medical records, medical data analysis (big data), teaching and the regulation of payment for medical services. If technological advances continue along these lines, it could bring about a revolution in medicine as we know it.

Pauline Bernard, Laurent Praly

No abstract is available for this record.

Jian Yang, Zhihui Lu, Jie Wu

No abstract is available for this record.

V. S. Dhillon

No abstract available.
 Editor’s note: A proposal to implement distributed ledger technology for electronic health records is outlined here. The rationale for integration of distributed ledgers in the healthcare domain is introduced, followed by a discussion of the features enabled by the use of a blockchain. An open source implementation of a distributed ledger is then presented. The article concludes with an examination of opportunities and challenges ahead in deploying blockchains for digital health.

Eric Zhang, C Hendrik, Yang Liu, Archit Sharma · 5 authors

In this paper we present the initial design of Minerva consensus protocol for Truechain and other technical details. Currently, it is widely believed in the blockchain community that a public chain cannot simultaneously achieve high performance, decentralization and security. This is true in the case of a Nakamoto chain (low performance) or a delegated proof of stake chain (partially centralized), which are the most popular block chain solutions at time of writing. Our consensus design enjoys the same consistency, liveness, transaction finality and security guarantee, a de-facto with the Hybrid Consensus. We go on to propose the idea of a new virtual machine on top of Ethereum which adds permissioned-chain based transaction processing capabilities in a permissionless setting. We also use the idea of data sharding and speculative transactions, and evaluation of smart contracts in a sharding friendly virtual machine. Finally, we will briefly discuss our fundamentally ASIC resistant mining algorithm, Truehash.

Ronghua Xu, Yu Chen, Erik Blasch, Genshe Chen

While the Internet of Things (IoT) technology has been widely recognized as the essential part of Smart Cities, it also brings new challenges in terms of privacy and security. Access control (AC) is among the top security concerns, which is critical in resource and information protection over IoT devices. Traditional access control approaches, like Access Control Lists (ACL), Role-based Access Control (RBAC) and Attribute-based Access Control (ABAC), are not able to provide a scalable, manageable and efficient mechanism to meet the requirements of IoT systems. Another weakness in today's AC is the centralized authorization server, which can be the performance bottleneck or the single point of failure. Inspired by the smart contract on top of a blockchain protocol, this paper proposes BlendCAC, which is a decentralized, federated capability-based AC mechanism to enable an effective protection for devices, services and information in large scale IoT systems. A federated capability-based delegation model (FCDM) is introduced to support hierarchical and multi-hop delegation. The mechanism for delegate authorization and revocation is explored. A robust identity-based capability token management strategy is proposed, which takes advantage of the smart contract for registering, propagating and revocating of the access authorization. A proof-of-concept prototype has been implemented on both resources-constrained devices (i.e., Raspberry PI node) and more powerful computing devices (i.e., laptops), and tested on a local private blockchain network. The experimental results demonstrate the feasibility of the BlendCAC to offer a decentralized, scalable, lightweight and fine-grained AC solution for IoT systems.

Doriane Perard, Jérôme Lacan, Yann Bachy, Jonathan Detchart

The concept of a decentralized ledger usually implies that each node of a blockchain network stores the entire blockchain. However, in the case of popular blockchains, which each weigh several hundreds of GB, the large amount of data to be stored can incite new or low-capacity nodes to run lightweight clients. Such nodes do not participate to the global storage effort and can result in a centralization of the blockchain by very few nodes, which is contrary to the basic concepts of a blockchain. To avoid this problem, we propose new low storage nodes that store a reduced amount of data generated from the blockchain by using erasure codes. The properties of this technique ensure that any block of the chain can be easily rebuild from a small number of such nodes. This system should encourage low storage nodes to contribute to the storage of the blockchain and to maintain decentralization despite of a globally increasing size of the blockchain. This system paves the way to new types of blockchains which would only be managed by low capacity nodes.