On Finality in Blockchains

This paper focuses on blockchain finality, which refers to the time when it becomes impossible to remove a block that has previously been appended to the blockchain. Blockchain finality can be deterministic or probabilistic, immediate or eventual. To favor availability against consistency in the face of partitions, most blockchains only offer probabilistic eventual finality: blocks may be revoked after being appended to the blockchain, yet with decreasing probability as they sink deeper into the chain. Other blockchains favor consistency by leveraging the immediate finality of Consensus - a block appended is never revoked - at the cost of additional synchronization. The quest for "good" deterministic finality properties for blockchains is still in its infancy, though. Our motivation is to provide a thorough study of several possible deterministic finality properties and explore their solvability. This is achieved by introducing the notion of bounded revocation, which informally says that the number of blocks that can be revoked from the current blockchain is bounded. Based on the requirements we impose on this revocation number, we provide reductions between different forms of eventual finality, Consensus and Eventual Consensus. From these reductions, we show some related impossibility results in presence of Byzantine processes, and provide non-trivial results. In particular, we provide an algorithm that solves a weak form of eventual finality in an asynchronous system in presence of an unbounded number of Byzantine processes. We also provide an algorithm that solves eventual finality with a bounded revocation number in an eventually synchronous environment in presence of less than half of Byzantine processes. The simplicity of the arguments should better guide blockchain designs and link them to clear formal properties of finality

X-BORDER PLATFORMS: THE IMPLICATIONS OF DISTRIBUTED LEDGER TECHNOLOGY

Distributed Ledger Technology (DLT) has been argued to play a vital role in facilitating cross-border payments and improving the financial ecosystem at a global scale. This research builds upon digital platform literature to frame cross-border payment organisations and uses a case study within the remittance industry to review the potential shapes of DLT within these platforms. Findings suggest that DLT can play a role at removing inefficiencies and promoting financial inclusion in developing countries by being used as a settlement mechanism, as a standardised communication channel and as a way for consolidating data located within the boundaries of different platforms. This study contributes to digital platform and DLT literature by suggesting three potential implications that this phenomenon can bring and their relevance to payment platforms

Sustainable Development Report: Blockchain, the Web3 & the SDGs

This is an output paper of the applied research that was conducted between July 2018 - October 2019 funded by the Austrian Development Agency (ADA) and conducted by the Research Institute for Cryptoeconomics at the Vienna University of Economics and Business and RCE Vienna (Regional Centre of Expertise on Education for Sustainable Development).Series: Working Paper Series / Institute for Cryptoeconomics / Interdisciplinary Researc

Sustainable Development Report: Blockchain, the Web3 & the SDGs

This is an output paper of the applied research that was conducted between July 2018 - October 2019 funded by the Austrian Development Agency (ADA) and conducted by the Research Institute for Cryptoeconomics at the Vienna University of Economics and Business and RCE Vienna (Regional Centre of Expertise on Education for Sustainable Development).Series: Working Paper Series / Institute for Cryptoeconomics / Interdisciplinary Researc

Is blockchain an emerging tool able to provide assistance to transitional justice processes?

Dissertação para a obtenção do grau de Mestre em Direito, na especialidade de Direito Internacional e EuropeuBlockchain technology has the capacity to change how people live, communicate with each other, acquire products, store information, and exchange data. Such technology – that is able to perform in different segments is being called a general-purpose technology, like the internet, - can be useful in transitional justice processes. The present paper intends to analyse the use of blockchain technology as a new component in transitional justice processes, understand how blockchain would behave in each transitional justice pillar, considering a state of the art situation. Subsequently, blockchain projects were mentioned, that could be used in transitional justice scenarios, such as the economic development of local communities, and the implementation of refugees’ digital identification. Lastly, the technology’s limitations were taken into consideration, leading to the conclusion that in considering implementing blockchain technology in transitional justice processes, it is crucial to ponder the local transitional justice scenario with the blockchain characteristics, in order to pursuit better results.A tecnologia blockchain tem a capacidade de mudar a forma como as pessoas vivem, se comunicam, adquirem produtos, guardam e trocam informações. O uso de tal tecnologia, capaz de atuar em múltiplos segmentos, sendo considerada uma tecnologia de propósito geral, como a internet, pode ser bem desfrutada em processos de justiça de transição. A presente dissertação tem como objetivo analisar se a tecnologia blockchain pode ser um novo componente em processos de justiça de transição, entendendo como a tecnologia atuaria, em cada pilar da justiça de transição, considerando um cenário de estado da arte. Posteriormente, foram citados alguns projetos nos quais se usa o blockchain e que poderiam ser usados em processos de justiça de transição, como desenvolvimento econômico de comunidades locais e implementação de identidades digitais para refugiados. Por fim, levou-se em consideração as limitações da tecnologia frente as suas circunstâncias atuais. Assim, antes de implementar a tecnologia blockchain em um cenário de justiça de transição, é importante ponderar todos os aspectos concretos da situação, juntamente com todas as características da tecnologia, para ter o melhor resultado