The objective of this thesis paper is to investigate whether if smart contracts concluded on a blockchain are recognized as contracts under Swedish law. This is done by analyzing two fictional examples of concluded smart contracts. The study shows that smart contracts may indeed be recognized as contracts as they fulfill mechanisms for concluding contracts that are regulated in the Swedish Contracts Act, such as offer-acceptance. Smart contracts may also be concluded on mechanisms that are not directly regulated by the Contracts Act, these include tacit agreements and standard form of contracts. The objective also includes discussions regarding certain legal issues that are raised by the blockchain and smart contracts. For instance, what problems an immutable blockchain may pose for the possibility to recall an offer or acceptance stated in the Contracts Act. Another aspect that may also potentially prove troublesome is the smart contracts self-fulfillment. This is because they can facilitate the automatic fulfillment of contracts that are null and void due to the fact that they comprise illegal or immoral undertakings.

Blockchain is an interesting technology, with different projects developing every day since it first gained its light back in 2008. More and more research finds blockchain useful in several different sectors. One of the sectors being healthcare, specifically for electronic health records (EHR). EHR contains highly sensitive data which is critical to protect and, just in the year 2019, 41,232,527 records were deemed stolen. Blockchain can provide several benefits when it comes to EHR, such as increased security, availability, and privacy, however, it needs to be done correctly. Due to blockchain being a rather novel technology, there is room for improvement when it comes to integrating blockchain with EHR. In this thesis a framework for EHR in the healthcare sector is proposed, using Ethereum based smart contracts together with decentralized off-chain storage using InterPlanetary File System (IPFS) and strong symmetric encryption. The framework secures the records and provides a scalable solution. Furthermore, a discussion and evaluation regarding several security aspects that the framework excels on as well as what the framework could improve on.

NFT-teknologin blir mer och mer populär för varje år som går, och under det senaste året hardet mer än dubblerat sitt marknadsvärde från ungefär 22 miljarder dollar till 44 miljarder dollar.Teknologin har applicerats på olika områden och vissa forskare förutspår att teknologinkommer att vara en stor del av Web3 och framtidens internet. Som de flesta andra teknologierfinns det hinder som kan hindra utvecklingen och appliceringen av teknologin. Det är viktigt attidentifiera vilka hinder som teknologin står framför samt få en förståelse för hur dessa hinderfungerar och påverkar.Syftet med denna studie är att undersöka vilka hinder som finns för utvecklingen avNFT-teknologi. Detta görs med en multimetod som kombinerar en intervjustudie och enlitteraturstudie. Intervjustudien genomfördes med fyra semi-strukturerade intervjuer med fyrarespondenter som alla arbetar med NFT. Litteraturstudien undersökte två databaser ochresulterade i 18 artiklar som analyserades. Resultatet från de båda metoderna analyseradessedan med metodtriangulering. Resultatet av studien blev att det identifierades 12 unika hindersom presenteras och analyseras.

Real estate assets are often considered as illiquid due to capital and transaction barriers. As a response, real estate tokenizing is a rising phenomenon. Real estate tokenizing combines the benefits from the private and the public real estate market, by creating a product with direct real estate commitment to low capital requirements and efficient transaction processes. The product is called real estate token, a digital share of an asset. Real estate tokens enable hypothetical fractionalization of properties with means of blockchain technology and smart contracts. This study investigate the pros and cons of real estate tokenizing as well as the financial performance of publicly traded US residential real estate tokens. The study states that fractionalization of properties increases access and customizability of real estate investments. Furthermore, the blockchain technology and the smart contracts enable automatization of transaction processes and asset management. Altogether, the benefits may result in a higher liquidity. However, the study also states several drawbacks with real estate tokenizing, such as lack of management and deeds, scalability problems and liquidity paradoxes. Furthermore, this study shows that US residential real estate tokens underperform both S&P 500 and housing index in terms of risk-adjusted return. Moreover, the real estate token market seems to correlate more with the S&P 500 than with the housing market. The study concludes that the cons with real estate tokenizing exceed the pros, although the phenomenon has great potential in a more mature market. However, real estate tokenizing will face implementation obstacles when converting the real estate industry to blockchain technology. As such, the success of real estate tokenizing is dependent on the global view of blockchain technology. / Fastigheter betraktas ofta som illikvida på grund av kapital- och transaktionsbarriärer. Som svar på den bristande likviditeten är blockchainteknologi inom fastigheter, även känt som ”real estate tokenizing”, ett växande fenomen. Real estate tokenizing ämnar till att kombinera fördelarna från den privata och den publika fastighetsmarknaden genom att skapa en produkt med direkt fastighetsexponering till låga kapitalkrav och effektiva transaktionsprocesser. Produkten kallas ”real estate token”, en digital andel av en tillgång. Real estate tokens möjliggör hypotetisk fraktionering av fastigheter med hjälp av blockchainteknologi och smarta kontrakt. Denna studie undersöker för- och nackdelar med real estate tokenizing såväl som finansiell prestation av publikt handlade real estate tokens inom det amerikanska bostadssegmentet. Studien konstaterar att fraktionering av fastigheter ökar tillgängligheten och anpassningsbarheten i fastighetsinvesteringar. Vidare möjliggör blockchainteknologi och smarta kontrakt automatisering av transaktionsprocesser och förvaltning. Sammantaget kan fördelarna med real estate tokenizing leda till högre likviditet. Studien konstaterar emellertid också flera nackdelar med real estate tokenizing, såsom brist på management och panträtt, storskalbarhetsproblem och likviditetsparadoxer. Vidare visar studien på att publikt handlade real estate tokens inom det amerikanska bostadssegmentet underpresterar både S&P 500 och bostadsindex i termer av riskjusterad avkastning. Dessutom verkar marknaden för publikt handlade real estate tokens inom det amerikanska bostadssegmentet korrelera mer med S&P 500 än med bostadsmarknaden. Studien konkluderar att nackdelarna med real estate tokenizing överstiger fördelarna i dagsläget, även om fenomenet har stor potential på en mer mogen marknad. Real estate tokenizing riskerar dock att möta implementeringshinder när fastighetsbranschen ska konverteras till blockchainteknologi. Således är framgången för real estate tokenizing beroende av den globala synen på blockchainteknologi.

This thesis investigated the use of Large Language Models (LLMs) for vulnerability analysis of decompiled smart contracts. A controlled experiment was conducted in which an automated system was developed to decompile smart contracts using two decompilers: Dedaub and Heimdall-rs, and subsequently analyze them using three LLMs: OpenAI’s GPT-4 and GPT-3.5, as well as Meta’s CodeLlama. The study focuses on assessing the effectiveness of the LLMs at identifying a range of vulnerabilities. The evaluation method included the collection and comparative analysis of performance and evaluative metrics such as the precision, recall and F1-scores. Our results show the LLM-decompiler pairing of Dedaub and GPT-4 to exhibit impressive detection capabilities across a range of vulnerabilities while failing to detect some vulnerabilities at which CodeLlama excelled. We demonstrated the potential of LLMs to improve smart contract security and sets the stage for future research to further expand on this domain.

Bakgrund: Intresset för världens första kryptovaluta Bitcoin har fått världen att öppna upp ögonen för dess underliggande teknologi: Blockkedjan (”Blockchain”). Blockkedjan kan beskrivas som en decentraliserad databas där ingen central aktör ensam kan bestämma över nätverket. Istället registreras och verifieras transaktioner av nätverkets deltagare. Detta möjliggör för digital information att distribueras men inte kopieras på ett tillförlitligt sätt. Teknologin har således möjlighet att skapa tillit mellan aktörer som vanligtvis inte litar på varandra och anses därför ha stor potential att effektivisera många branscher, däribland banksektorn. Det råder en stor optimism bland flertalet finansiella aktörer som undersöker vilka möjligheter teknologin har att förbättra dess produkter och tjänster. Syfte: Studiens syfte är att undersöka vilka användningsområden svenska banker ser potential för Blockkedjan och hur teknologin kan komma att appliceras inom banksektorn. Studien ämnar även analysera vilka effekter användningen av Blockkedjan kan få på transaktioner inom den svenska banksektorn. Genomförande: Studien karaktäriseras av en kvalitativ forskningsmetod. Empirinsamlingen har skett genom ett selekterat urval med fokus på individer som är insatta inom ämnet och banksektorn. Slutsats: Studien identifierar KYC, Smarta Kontrakt och Transaktioner som potentiella användningsområden för den svenska banksektorn. Framförallt KYC lyfts fram som ett område där blockkedjeteknologi kan spela en framtida roll i att förbättra hanteringen av kundinformation. Studien framhäver även trade finance och interbank-transaktioner som attraktiva områden för teknologin att effektivisera. Vidare visar resultatet att Blockkedjan inte skall ses som ett hot mot bankernas roll som intermediär utan en teknologi som möjliggör effektivisering av deras befintliga tjänster. Teknologin är att betrakta som en Emerging technology med en hög osäkerhet i dagsläget där teknologins största potential att ge effekt ligger i framtiden. De största hoten mot en implementering av blockkedjeteknologin inom banksektorn är att teknologin fortfarande befinner sig i en experimentell fas samt en brist på gemensamma standarder och regler banker och länder emellan. / Background: The interest for the first cryptocurrency in the world made the world caught the attention of the technology behind Bitcoin: Blockchain. Blockchain can be described as a decentralized database with no central part controlling its network. Instead, all transactions are registered and verified by the members of the network. This enables digital information to be distributed but not copied in a trustworthy way. The technology therefore has the possibility to create trust between parties that normally does not trust each other and is for that reason considered to have the potential to make many industries, including the banking industry more effective. Amongst a number of financial players that investigate the possible opportunities the technology have for improving their products and services, the optimism is high. Purpose: The purpose of this study is to research which potential fields of application Swedish banks sees for Blockchain and how the technology could be used by the banking industry. The study also intend to analyze the effects the usage of the technology would have on transactions within the Swedish banking industry. Completion: A qualitative research method characterize the study. The empirical data has been collected through a selected sample focused on individuals with knowledge and experience within the field. Conclusion: The study identifies KYC, Smart Contracts and Transactions as potential fields of application for the Swedish banking industry. In particular, KYC was highlighted as an area where the Blockchain technology could help improve managing the personal information of the customer. The study also points out trade finance and interbank-transactions as attractive areas of possible use for the technology. Furthermore, the result of the study shows that the technology should not be seen as a threat against banks role as an intermediary but a technology that enables the banks services to become more efficient. The technology is to be seen as an Emerging technology with high uncertainty today and where the potential impact lays in the future. The biggest threats against an implementation of the technology are that the technology still is in an experimental phase and the shortage of common standards and rules between banks and across countries.

The world is becoming more and more digitized. Recently many industries have started to research the blockchain technology and particularly smart contracts. One industry that so far has not adopted new technology in the same pace as other industries, is the insurance industry so this interview study aims at finding opportunities and challenges for insurance companies that want to learn about smart contracts and its use cases.By doing a literature review and performing interviews with blockchain experts and insurance company employees, this study found that both IT companies working with smart contracts and the insurance companies have limited knowledge of the legal aspect of smart contracts. The lack of standards and regulations allows IT companies to freely create smart contracts without much quality control. The insurance companies must innovate themselves in order to not be disrupted. The blockchain technology will offer many new insurance types and if the insurance industry fails to adopt the blockchain technology they may face market disruption.There is much room for future research following this study. It would be beneficial to research how contract theory could be used in practice during the creation of legally binding smart contracts. Furthermore, research around fraud prevention in smart contracts would be interesting as would an in-depth exploration of the ecosystem of third party software and services around smart contracts.

Under de senaste åren har blockchain-tekniken fått mer och mer uppmärksamhet. Det har visat speciella fördelar i digital valuta, eftersom det distribueras och dess data inte kan ändras. Med fler länder som presenterar idén om kraftsysteminnovationen har ett stort antal distribuerade kraftkällor dykt upp. Nätanslutningen för dessa distribuerade kraftkällor leder till instabil nätdrift och ökar svårigheten att hantera kraftigt. Därför finns det ett akut behov av en lösning som kan realisera direkt transaktion av distribuerad kraftförsörjning. Denna artikel gör en fördjupad analys av blockchain-tekniken, inklusive hasalgoritm, konsensusmekanism, Merkle-träd, smart kontrakt etc. Och sedan studeras Ethereum och smarta nät. Den här artikeln realiserar automatisering och intelligens för mätning av eltransaktioner genom smart kontraktsteknik som tillhandahålls av Ethereum. En blockchain privat kedja skapas och sedan distribueras det smarta kontraktet i den privata kedjan. Med fördelarna med blockchaintekniken ovan kommer lagring av kraftdata och krafttransaktioner att vara mer trovärdig och mer transparent. Sammantaget designar och bygger detta papper ett smart grid-system baserat på blockchain-smarta teknik. Systemet kan inte bara användas för smarta nätsystem utan även för andra energisystem. Denna artikel ger en referens för tillämpning av blockchain-teknik. / In recent years, blockchain technology has received more and more attention. It has shown special advantages in digital currency, because it is distributed and its data cannot be altered. With more countries put forward the idea of the power system innovation, a large number of distributed power sources have emerged. The grid connection of these distributed power sources will lead to unstable grid operation and greatly increase the difficulty of management. Therefore, there is an urgent need for a solution that can realize direct transaction of distributed power supply. This article makes an in-depth analysis of the blockchain technology, including hash algorithm, consensus mechanism, Merkle tree, smart contract, etc. And then the Ethereum and smart grids are studied. This article realizes automation and intelligence of the electricity transaction measurement through the smart contract technology provided by Ethereum. A blockchain private chain is created and then the smart contract is deployed into the private chain. With the advantages of blockchain technology aforementioned, the storage of power data and the power transactions will be more credible and more transparent. All in all, this paper designs and builds a smart grid system based on the smart contract technology of blockchain. The system can be used not only for smart grid systems but also for other energy trading systems. This article provides a reference for the application of blockchain technology.

Vilka möjligheter och utmaningar kan blockkedjetekniken erbjuda i revisionsprocessen? Studien ska undersöka samt skapa förståelse för de möjligheter och utmaningar som blockkedjetekniken medför inom revisionsprocessen och därmed bidra med ökad empirisk kunskap till det forskningsgap som identifierats inom den vetenskapliga litteraturen. Kvalitativ dokumentstudie som jämför vetenskapliga artiklar och dokument. De möjligheter som kan identifieras med blockkedjetekniken är trippelbokföring, smarta kontrakt, minskad tid, minskad kostnad, minskad risk, kodade kreditvärdighetsmodeller, minskat antal rättstvister, förenklar revisionsprocessen, blockkedjetekniken är omanipulerbar, ökad tillförlitlighet till revisorn, säkerhetskopiering, revisorn får en ny roll. De utmaningar som kan identifieras är ökad öppenhet, mindre transparens, kontrollera äkthet på överföringar, om blockkedjan kan manipuleras, farligt att lita till 100% på teknik, säkerhetskopiering, överskattad säkerhet, beskattning i realtid, skalbarhet, kostnader ökar i början, ekonomiutbildningar behöver anpassas, revisorns nya roll, revisorns nya arbetsuppgifter, nya kompetenser krävs, etik behövs, lagar och regler behöver anpassas, lagar behöver tillföras snabbare. Det är tydligt att många av möjligheterna också innebär utmaningar, det är sällan en möjlighet nämns utan att utmaningar med densamma tas upp. Det som också syns tydligt är att utmaningarna med blockkedjetekniken i dagsläget är fler än möjligheterna, vilket var ett oväntat resultat. / What opportunities and challenges can blockchain technology offer in the auditprocess? The study will investigate and create an understanding of the opportunities and challenges that blockchain technology entails in the audit process, thereby contributing with increased empirical knowledge to the research gap identified in the scientific literature. Qualitative documentstudy comparing scientific articles and documents. The opportunities that can be identified with blockchaintechnology are trippleaccounting, smart contracts, reduced time, reduced cost, reduced risk, coded creditworthiness models, reduced number of litigations, simplifies the auditprocess, blockchaintechnology is unmanipulable, increased reliability to the auditor, back-up, auditor’s new role. The challenges that can be identified are increased openness, less transparency, checking the authenticity of transfers, if the blockchain can be manipulated, dangerous to trust 100% on technology, backup, overestimated security, real-time taxation, scalability, costs increase in the beginning, financial education needs to be adapted , the auditor's new role, the auditor's new duties, new skills are required, ethics are needed, laws and regulations need to be adapted, laws need to be applied more quickly. It is clear that many of the opportunities also pose challenges; there is rarely an opportunity mentioned without challenges being addressed. What is also clearly seen is that the challenges with blockchain technology in the current situation are many more than the possibilities, which was an unexpected result.

Blockchains, smart contracts and cryptocurrencies are reaching further global adoption each day and are becoming more prominent to be the foundation for a new technological era and to be used in transactions globally. The technology has strong coherent properties, including a high level of security, decentralization, and its use of smart contracts to obviate intermediaries. These technologies offer the possibility to do any transaction without a centralized bank controlling, denying, or reversing the transaction. This report aims to shed light on blockchain technologies possible impact on society and if the current centralized-based system can be replaced or if it is deemed as necessary. What the potential outcome would be if these centralized authorities sees a decrease in power and how blockchains, smart contracts and stablecoins can be used as an everyday payment and transaction system, excluding all third parties. To do this, a literature review, a quantitative survey, and qualitative interviews were conducted. The literature review, to lay the ground for the questions in the survey, interviews, and additionally, to determine what blockchain and what kind of stablecoin is most suited for global adoption. The result from the qualitative interview were to acquire knowledge from more experienced individuals working or owning a company that is based on top of blockchains. Lastly, considering blockchain technology and web 3.0 is still under development and yet to become globally accepted, the questionnaire survey was conducted to retrieve the general consensus from individuals inside crypto communities. The report overall, came out to be successful, indicating that blockchain technologies has a bright future and that the decentralization it adds to society can benefit the individual in multiple of different ways, specifically in the financial sector. However, although the conclusion that blockchain technologies can be used as a global payment system were deemed successful, objective, and subjective opinions were discussed and reported relevant, whereas one individual might view the exclusion of intermediaries as necessary and beneficial, while the other – as something negative. Scalability issues in blockchains and smart contracts controversy, such as its complexity and its immutability aspect are also analyzed and discussed as a potential hindrance for further global adoption.