7 research outputs found

    Oracular Byzantine Reliable Broadcast

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    Byzantine Reliable Broadcast (BRB) is a fundamental distributed computing primitive, with applications ranging from notifications to asynchronous payment systems. Motivated by practical consideration, we study Client-Server Byzantine Reliable Broadcast (CSB), a multi-shot variant of BRB whose interface is split between broadcasting clients and delivering servers. We present Draft, an optimally resilient implementation of CSB. Like most implementations of BRB, Draft guarantees both liveness and safety in an asynchronous environment. Under good conditions, however, Draft achieves unparalleled efficiency. In a moment of synchrony, free from Byzantine misbehaviour, and at the limit of infinitely many broadcasting clients, a Draft server delivers a b-bits payload at an asymptotic amortized cost of 0 signature verifications, and (log?(c) + b) bits exchanged, where c is the number of clients in the system. This is the information-theoretical minimum number of bits required to convey the payload (b bits, assuming it is compressed), along with an identifier for its sender (log?(c) bits, necessary to enumerate any set of c elements, and optimal if broadcasting frequencies are uniform or unknown). These two achievements have profound practical implications. Real-world BRB implementations are often bottlenecked either by expensive signature verifications, or by communication overhead. For Draft, instead, the network is the limit: a server can deliver payloads as quickly as it would receive them from an infallible oracle

    Carbon: An Asynchronous Voting-Based Payment System for a Client-Server Architecture

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    We present Carbon, an asynchronous payment system. To the best of our knowledge, Carbon is the first asynchronous payment system designed specifically for a client-server architecture. Namely, besides being able to make payments, clients of Carbon are capable of changing the set of running servers using a novel voting mechanism -- asynchronous, balance-based voting

    Rapporto sul sistema agro-alimentare in Abruzzo 2018

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    Il Rapporto sul sistema agro-alimentare in Abruzzo 2018 ha la finalitĂ  di fornire una chiave di lettura dello sviluppo regionale del comparto agroalimentare abruzzese, ponendosi come strumento di analisi e riflessione a disposizione delle imprese, delle istituzioni e dei cittadini. I contenuti tematici del rapporto spaziano dagli aspetti prettamente economici a quelli tecnico-organizzativi, politici, di comunicazione, di tutela ed innovazione, mettendo in luce un quadro completo del sistema agroalimentare regionale. Il rapporto costituisce la naturale prosecuzione del volume L'agroalimentare abruzzese tra crisi e crescita edito nel 2014 ed ha previsto la collaborazione fra docenti, ricercatori e professionisti appartenenti al mondo dell'UniversitĂ  e ai Centri di Ricerca del territorio

    Methodological Comparison of Different Projects

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    In order to compare the methodological aspects of the different projects, while also placing them within a common framework, a form was specially drafted. This form was filled out in May 2019 by one or more members of each work group (Ascoli Piceno, Bologna, Milano, Roma, Trieste). The form was divided into three different sections (“Context characterisation methods”; “Community involvement methods”; “Networking methods”). Each section was created in order to highlight multidisciplinary aspects, the collaboration among different roles, and the problems and limitations the could have been faced. The sections differ in their design, although a common scheme was used in nearly all parts: narrative description, players, actions, instruments and sources. Consequently, all projects were therefore analysed according to the following matrix. Considering the specificity of the Recovery-Net project, this project was analysed solely for context characterisation methods
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