Open-Source Legal Process Designer in .NET Blazor

Tato práce se zabývá průzkumem frameworku Blazor a tvorbou prototypu editoru chytrých blockchain smluv. Editor chytrých smluv by mohl být schopen tvořit decentralizované, autonomní a zabezpečené elektronické smlouvy, a to za použití vizuálního a uživatelsky přívětivého jazyka DasContract. Chytré smlouvy mohou významně snížit množství administrativní práce a v některých případech i eliminovat potřebu centrálních autorit, například bank. V rámci této práce byl zanalyzován, navržen a implementován editor chytrých smluv. Funkčnost editoru byla demonstrována vytvořením hypoteční smlouvy. Zdrojový kód editoru je veřejně dostupný pro další potenciální výzkum. Tato práce také posoudila a shrnula přínosy frameworku Blazor a porovnala jej s ostatními SPA frameworky.This thesis focuses on an exploration of a single page application framework called Blazor and a proof of concept implementation of a Blockchain Smart Contract editor. The Smart Contract editor has the potential to create decentralized, autonomous, and secure electronic contracts, using a user-friendly visual language DasContract. Such contracts could significantly reduce various administration tasks and in some cases eliminate the need for central authorities, such as banks. In this thesis, a proof of concept implementation of a Smart Contract editor is analyzed, designed, and implemented. The functionality of the editor was demonstrated in a case study of a mortgage contract. The editors' source code is publicly available for further research. This thesis also reviewed and summarised the benefits of Blazor and compared it to other single page application frameworks

Smart Contract Languages: A Multivocal Mapping Study

Blockchain is a disruptive technology that has attracted the attention of the scientific community and compa nies, as proven by the exponential growth of publications on this topic in recent years. This growing interest is mainly due to the promise that the use of blockchain enables it to be verified, without including any trusted intermediaries, that the information received from the network is authentic and up-to-date. In this respect, blockchain is a distributed database that can be seen as a ledger that records all transactions that have ever been executed. In this context, smart contracts are pieces of software used to facilitate, verify, and enforce the negotiation of a transaction on a blockchain platform. These pieces of software are implemented by using programming languages, which are sometimes provided by the blockchain platforms themselves. This study aims to (1) identify and categorise the state-of-the-art related to smart contract languages, in terms of the existing languages and their main features, and (2) identify new research opportunities. The review has been conducted as a multivocal mapping study that followsthe guidelines proposed by Garousi et al. for conducting multivocal literature reviews, as well as the guidelines proposed by Kitchenham and Charters for conducting mapping studies. As a result of the implementation of the review protocol, 4,119 papers were gathered, and 109 of them were selected for extraction. The contributions of this article are twofold: (1) 101 different smart contract languages have been identified and classified according to a variety of criteria; (2) a discussion on the findings and their implications for future research have been outlined. As a conclusion, it could be stated that a rigorous and replicable overview of the state-of-the-art of smart contract languages has been provided that can benefit not only researchers but also practitioners in the field, thanks to its multivocal nature.Ministerio de Ciencia y Tecnología RTI2018-094283-B-C33 (ECLIPSE)Junta de Andalucía COPERNICA (P20-01224)Junta de Andalucía METAMORFOSIS (US-1381375

Dissecting Smart Contract Languages: A Survey

Blockchain is a distributed ledger technology that gained popularity for enabling the transformation of cryptocurrency among peers without mediation by a centralized third-party authority. Smart contracts expand the applications of blockchain technology and have played a role in its widespread adoption. Smart contracts are immutable digital programs that are deployed on blockchains to codify agreements between parties. Existing smart contract implementations have faced challenges, including security vulnerabilities, leading to significant losses and concerns. This has stimulated a wave of attempts to improve Smart Contract Languages (SCLs) to overcome implementation challenges and ensure code quality, producing many languages with diverse features. Scholars have made some attempts to classify SCLs and clarify the process of selecting an SCL, but to the best of our knowledge, no comprehensive survey of existing SCLs has been published. Our work surpasses earlier efforts by evaluating a significantly larger set of SCLs, in greater depth, to ease the process of SCL selection for blockchain research and implementation. In this paper, we (1) propose a robust framework for comparing existing SCLs, (2) analyze and discuss 36 SCLs, addressing issues beyond those used to construct the comparison framework, and (3) define new parameters for future research and development of SCLs. The survey provides a guide for those who intend to select or use an SCL to implement smart contracts, develop new SCLs, or add new extensions to the existing SCLs

Deciphering the Nexus: Blockchain-Smart Contracts and Their Transformative Potential in the Construction Industry

The construction industry, characterized by its intricate processes and extensive stakeholder networks, stands at the cusp of a digital revolution. The adoption of blockchain-smart contract (BCSC) technology is at the heart of this transformation. This research delves deep into the BCSC within the construction arena to provide comprehensive insight into its probable applications, inherent challenges, and potential future trajectories. Leveraging the PRISMA analysis technique, a curated collection of relevant academic research articles was assembled, shedding light on the existing body of knowledge regarding the application of BCSC technology in construction. The authors developed an innovative user interface tool customized to automatically analyze Excel files exported from Scopus and Science Direct databases to ensure a rigorous approach. Preliminary findings highlight the existing gaps between the theoretical potential of blockchain and its tangible implementation in the construction domain. This study consolidates existing literature and emphasizes the critical domains and key parameters that future studies should address. The paper paves the way for innovative breakthroughs by pinpointing these gaps, pushing the boundaries of how blockchain and smart contracts might reshape the construction industry\u27s future landscape

Atas das Oitavas Jornadas de Informática da Universidade de Évora

Atas das Oitavas Jornadas de Informática da Universidade de Évora realizadas em Março de 2018

A Comparison of Approaches for Visualizing Blockchains and Smart Contracts

The use of blockchains and smart contracts is currently explored in various fields of science and engineering due to their potential of radically changing the ways of doing business and the assumed elimination of traditional legal entities. Thereby, the complexity of the underlying technical relationships and mechanisms typically hampers the understanding by non-technical experts. In this paper we review approaches for visualizing blockchains and smart contracts. The investigation focuses on design and analysis approaches, concluding with requirements for a visual modelling language

Deciphering the Nexus: Blockchain-Smart Contracts and Their Transformative Potential in the Construction Industry

The construction industry, characterized by its intricate processes and extensive stakeholder networks, stands at the cusp of a digital revolution. The adoption of blockchain-smart contract (BCSC) technology is at the heart of this transformation. This research delves deep into the BCSC within the construction arena to provide comprehensive insight into its probable applications, inherent challenges, and potential future trajectories. Leveraging the PRISMA analysis technique, a curated collection of relevant academic research articles was assembled, shedding light on the existing body of knowledge regarding the application of BCSC technology in construction. The authors developed an innovative user interface tool customized to automatically analyze Excel files exported from Scopus and Science Direct databases to ensure a rigorous approach. Preliminary findings highlight the existing gaps between the theoretical potential of blockchain and its tangible implementation in the construction domain. This study consolidates existing literature and emphasizes the critical domains and key parameters that future studies should address. The paper paves the way for innovative breakthroughs by pinpointing these gaps, pushing the boundaries of how blockchain and smart contracts might reshape the construction industry\u27s future landscape

Provas de Coerência Transacional para Smart Contracts em Blockhains

Blockchain technology is an emergent topic based on decentralization and immutability, enabling mutually untrusting parties to fairly exchange assets without the need of a central authority. Recently, the addition of blockchain programs, known as smart contracts, enabled the technology to expand upon a variety of industry sectors, already known to traditional software. Many organizations and corporates saw a growth opportunity, extending their businesses into this domain — now, though, with the blockchain twist. However, the inclusion of computation exposed a weak link in the overall blockchain security, due to carrying not only traditional software bugs, but also never before seen ones. That way, smart contracts, especially valuable ones, became enticing for hackers to exploit, which resulted in a set of tragedies where funds were stolen, among other consequences. Soon after, smart contract security became a most valuable topic of research among blockchain platforms. The Tezos blockchain is a relatively new platform whose stance values security by construct infrastructure, in consequence of the past incidents. While many smart contract security solutions were devised over the years, these have not been properly adapted nor adopted for the average developer in the community. Due to various reasons, but for one, seamless integration with the smart contract development processes is one of them. This dissertation approaches the blockchain security problem through an indirect approach, providing the developer with better accessibility and conditions for working on one of Tezos’s state-of-the-art security tools. Although it is unorthodox, it is hoped for the solution to inspire and appeal other blockchain communities by shedding some light in this unknown direction.A tecnologia blockchain é um tópico emergente baseado na descentralização e imutabilidade, permitindo que entidades desconhecidas e não confiáveis consigam trocar bens e valores digitais de forma justa sem necessitarem uma entidade central. Recentemente, a adição de programas na blockchain, designados de smart contracts, permitiu que tal se expandisse sobre uma variedade de sectores industriais já explorada por programas tradicionais. Contudo, muitas empresas viram uma oportunidade de negócio bastante lucrativa, estendendo o seu negócio para este ambiente, agora incutindo as regras da blockchain. Embora oportunidades lucrativas tenham aparecido, problemas relativos aos programas tradicionais, bem como outros novos ainda não descobertos, também. Os smart contracts revelaram-se como um elo mais fraco para a segurança da blockchain e, tendo estes a capacidade de reter bastante valor monetário, tornaram-se um alvo aliciante para hackers. Não muito depois, notícias espalharam-se pela internet a anunciar crimes por entidades anónimas — roubo e congelamento de fundos, entre outras consequências, na blockchain. Após o primeiro grande incidente, a segurança na blockchain começou a ser um tópico bastante estudado por peritos e investigadores das várias comunidades. A blockchain da Tezos é uma plataforma relativamente recente, com uma postura relativa à segurança bastante madura, resultado dos incidentes passados. Enquanto várias soluções foram alcançadas para a segurança de smart contracts, estas não seriam ainda bem incorporadas pela comunidade, ou pelo menos para o engenheiro de contratos comum. Existem várias razões, porém, acessibilidade nos vários aspetos das ferramentas de segurança é uma delas. O trabalho realizado por esta dissertação passa por solucionar este problema, mais especificamente, solucionar o problema para uma ferramenta de segurança de programas na blockchain da Tezos. Este tipo de solução não é comum na literatura, contudo, espera-se que o trabalho realizado sirva de inspiração para que as comunidades possa explorar esta vertente mais indireta de segurança na blockchain

Modeling Business Processes on a Blockchain Ecosystem using CMMN

Plokiahela kohta on spekuleeritud, et see on “kõige olulisem leiutis pärast Internetti” ning et sellel on potentsiaal pakkuda märkmisväärset ärilist väärtust nii finants- kui ka teistes sektorites. Sellest tulenevalt on ettevõtted hakanud uurima, kuidas oleks neil võimalik oma äriprotsessides plokiahelatehnoloogiast kasu saada. Siiski, lihtsalt olemasolevate protsesside asendamine uute tehnoloogiatega ei paku soovitud tulemusi. Sellest tulenevalt disainitakse olukordades, kus protsessimudelid on protsessianalüüsi ning selle innovatsiooni aluseks, protsesse täiesti ümber. Käesolevas töös uuritakse, kuidas plokiahelale orienteeritud protsesse saab modelleerida CMMN modelleerimiskeele abil, kuna see on artefakti-põhine modellerimiskeel. Selline lähenemine võib olla eriti kasulik plokiahelale orienteeritud protsesside modelleerimisel, kuna plokiahelate peamine fookus on andmetel, mis on lisatud ahelasse ning jagatud erinevate osapoolte vahel. Käesolev töö põhineb juhtumianalüüsil, mis on läbi viidud mittetulundusühingus, mis tegeleb puidutoodetega kauplevate ettevõtete sertifitseerimisteenuste pakkumisega. Nimetatud organisatsiooni auditeerimisprotsessid kujundati ümber kasutades plokiahelat ning nutikaid lepingutehnoloogiaid, mille järel modelleeriti need kasutades CMMN modelleerimiskeelt. Analüüsimaks, kas CMMN modelleerimiskeel on plokiahelale tuginevate protsesside modelleerimiseks sobilik, kasutati raamistikku, mis hõlmab üldlevinud mustreid, mis on omased plokiahelale tuginevatele rakendustele. Selle tulemusena ilmnes, et CMMN modelleerimiskeele abil on võimalik plokiahelale tuginevaid protsesse üldiselt adekvaatselt kirjeldada, küll aga on siiski puudus elementidest modelleerimaks täpsemaid plokiahelatele ning nutikatele lepingutehnoloogiatele omaseid detaile.Blockchain has been speculated to be “the most important invention since the Internet” and has the potential to deliver significant business value for both financial and non-financial industries. That is why companies have started to explore how their business processes can benefit from this technology. However, a simple substitution of a current process with new technology will not provide desired outcomes. For this purpose, process redesign is used where process models are made the basis of process analysis and its innovation. This paper examines how blockchain-oriented processes can be modelled with CMMN as it is an artefact-centric modelling language. Such an approach might be particularly useful while modeling blockchain-oriented processes as the fundamental focus of blockchain is on data that is added on a chain and shared between participants. This paper is based on a case study of a non-profit organization providing certification services for companies trading timber-relates products. The auditing process of this organization was redesign using blockchain and smart contract technologies and then was modelled with CMMN. For analysis of the suitability of CMMN for modelling blockchain-based processes a framework for commonly occurring patterns that are specific to blockchain-based applications was used. As a result, CMMN can adequately represent blockchain-oriented processes. However, there is a lack of elements in the notation to accurately model certain details specific to blockchain and smart contract technologies

A User-Centered Perspective for the blockchain Development

Blockchain technology is regarded as one of the most important digital innovations in the last two decades. Its applicability beyond cryptocurrencies has been a growing topic of research interest not only in computer science but also in other areas, such as marketing, finance, law, healthcare, etc. However blockchain is far from reaching the population on a larger scale. The dissertation evaluates the causes that are preventing successful implementation and adoption of blockchain technology at a larger scale, supporting infrastructure for public and private companies. The latest academic research suggests that the blockchain services are still in an early stage, and standards for developing blockchain-based applications have not been defined yet. Moreover the interaction with the blockchain technology is still complex, especially for non expert users, because it requires many technical skills. The dissertation focuses on this knowledge gap as a cause for the blockchain missing reach on society at a larger scale. This work aims to fill the gap by presenting innovative methodologies and user-centered models that could help the adoption of the blockchain technology by a larger number of private/public companies and individuals. Based on these models, specific tools for both expert and non-expert users are developed and discussed in the dissertation. First, tools for expert users, i.e., software developers, are proposed to analyze the smart contracts’ source code, to collect the smart contracts in a reasoned repository, and to identify code clones and boost the use of open source libraries for a better collective practice in developing and maintaining the blockchain. Second, tools for non-expert users, i.e. people with no technical knowledge, are proposed to suggest them the fairest fees to pay to have their transactions executed according to the price and waiting times they are willing to spend, and to identify malicious smart contracts that can deceive them, thus preventing them to trust the blockchain and use it again. Finally, visualization models for users with expertise in different disciplines are proposed to provide them with graphical representations that can foster the understanding of the blockchain underlying mechanisms