This thesis investigates the security challenges of blockchain consensus mechanisms, arguing that sub-stratal to these challenges is the widely adopted mindset of probabilistic finality, which in itself is an inherent and significant vulnerability. Core to this problem is the inability or probabilistic protocols such a Proof of Work and Proof of Stake to provide the necessary deterministic and irreversible transaction settlement that high-integrity systems require. This is primarily due to their use of a “longest chain” rule. This deficiency is immensely amplified on new blockchains, as they do not possess the accumulated economic and computational security of mature networks. New blockchains face a serious “bootstrap security problem” which makes them highly prone to catastrophic 51% attacks. The research methodology follows a multi-stage, systematic approach, beginning with a comprehensive literature review to classify and analyse the existing threat landscape across major consensus protocols. Then a targeted theoretical critique of probabilistic finality is presented next, as is a systematic evidence-based assessment of some of the economic and architectural vulnerabilities of nascent networks. The findings of this analytical work confirm that the security of a blockchain is not static but evolves, and that the initial phase of a network's lifecycle is its most insecure. The main contribution of this thesis is the design and proposal of a novel consensus algorithm called “Erdos” that aims to address these issues directly. Erdos offers a deterministic process for block finalization that involves multiple rounds of vetting and a fair, resource-independent node selection. The design provides a strong fork resistance that stops the risk of 51% attacks and double spending right from the inception and launch of a network. Moreover, it reduces the centralisation pressure that proves to be a problem for nascent protocols. The primary implication of this research is that the future of secure, decentralised systems, particularly for new and emerging applications, necessitates an architectural shift away from probabilistic models towards deterministic, fair, and resilient consensus protocols as exemplified by the Erdos algorithm.
Consensus serves as a foundational mechanism in both social coordination and distributed technical systems. While machine consensus research in engineering focuses on fault tolerance and synchronization, social science emphasizes human deliberation, participation, and governance. However, the increasing convergence of human and machine decision making, exemplified by decentralized autonomous organizations (DAOs), intelligent agents, and cyber-physical social systems, demands a more integrated and theoretically robust understanding of consensus. This thesis addresses this interdisciplinary gap by investigating consensus across three interconnected dimensions: probabilistic fault-tolerant consensus systems, human-driven voting mechanisms in DAOs, and a unified conceptual framework bridging human and machine consensus. The first part of the thesis focuses on distributed fault-tolerant consensus in uncertain environments. Traditional approaches often rely on deterministic assumptions about node failures and fixed quorum rules. These assumptions may fail to reflect real-world systems where node behaviour is influenced by heterogeneous reliability and probabilistic failures. To address this limitation, a probabilistic modelling framework is proposed, treating node reliability as a stochastic variable. Within this framework, consensus outcomes are classified into three categories: safe, risky, and compromised. A new concept, referred to as the reliability quorum, is introduced to provide a more flexible threshold for achieving consensus based on targeted reliability levels. This model enables system designers to tailor fault tolerance according to specific reliability requirements, providing both analytical clarity and practical adaptability. The second part investigates consensus in decentralized systems primarily driven by human-oriented agents, using DAO voting as a representative case. In contrast to deterministic coordination among machines, DAO consensus arises from voluntary participation, heterogeneous voting power, and non-uniform approval conditions. To guide the analysis, the thesis introduces the DAO governance triangle alongside the SEED framework, which qualitatively evaluates voting mechanisms across four dimensions: Security, Efficiency, Effectiveness, and Decentralization. Building on this conceptual foundation, the study proceeds to a quantitative investigation of two key SEED dimensions. For decentralization, a stochastic process model is proposed to capture probabilistic participation and power distribution, leading to the formulation of the Consistency Rate and the Decentralization Coefficient as quantitative indicators. For efficiency, the model is further extended to characterize the interactions among participation probability, voting duration, and approval rate, enabling a formal evaluation of voting responsiveness and resource usage. Simulation results support both aspects of the analysis, revealing how power concentration, turnout behaviour, and mechanism design jointly influence decentralization and efficiency in DAO voting. The third part presents a unifying conceptual framework to analyse consensus across human, machine, and human-machine hybrid systems. Despite disciplinary differences, the thesis identifies three core components of any consensus process: participants (the actors of agreement), communication (the medium of exchange), and state (the evolving representation of agreement). Framing consensus as an entropy-reduction process that resolves cognitive or informational divergence, this abstraction enables comparative analysis across diverse systems. The framework also distinguishes among human consensus, machine consensus, and human-machine hybrid consensus, and offers design guidelines aligned with the characteristics and limitations of each. Together, these three threads construct a comprehensive theory of consensus that connects distributed computation, social governance, and emerging hybrid collectives. By integrating modelling, evaluation, and abstraction, this thesis contributes a multi-layered foundation for understanding and designing consensus mechanisms that are robust, scalable, and trustworthy in increasingly decentralized and intelligent environments.
Ayush Agnihotri, Ashutosh Pandey, Rajat Verma, Namrata Dhanda
This abstract delves into the transformative role of smart contracts and decentralized applications in Video DRM (Digital Rights Management). As digital content protection undergoes a paradigm shift, the integration of Video DRM, smart contracts, and DApps presents a pioneering approach to content management within the confluence of cryptography, blockchain, and artificial intelligence. Smart contracts, functioning as self-executing agreements, merge seamlessly with Video DRM principles, offering a secure and transparent means to encode content access rights, licensing terms, and royalty payments. DApps, residing on decentralized blockchain networks, harness this synergy to create tamper-resistant ecosystems for content distribution and digital rights management. This abstract highlight the potential of Video DRM, facilitated by smart contracts and DApps, to empower content creators, enabling them to securely manage their intellectual property within a trustless, automated, and auditable environment. The interplay between these technologies redefines content protection in the digital landscape, guarding the rights of creators and distributors alike.
The web is evolving from centralized servers and trusted intermediaries toward decentralized systems that empower users to own their data, assets, and identities. Decentralized applications connect familiar frontend interfaces to blockchains and smart contracts, shifting trust from corporations to transparent, self-executing code.
Financial industry operations have been substantially reformed through the adoption of decentralized applications (dApps) as well as blockchain technology during recent years. This research aims to handle three main issues within decentralised finance (DeFi) by focusing on transaction functionality execution and system scalability and enhanced security features. We implemented secure measures for integer overflows and reentrancy avoidance through extensive testing which proved successful in eliminating reentrancy gaps and integer overflows. The scalability tests demonstrated functioning performance with network congestion but bigger congestion caused noticeable delays alongside elevated latency levels. Due to the nature of large transaction processing additional optimization measures need implementation. The results of functional testing showed that 100% of token transfers succeeded together with 97.5% success rate for asset management operations. The success rate of decentralized trade operations reached 96% according to results. Smart contract implementations succeed in protecting transactions yet need additional work to increase scalability and improve decentralized exchange functions. The research concludes that smart contract-based DeFi solutions show substantial promise yet demands continuous advancement to gain more widespread market adoption.
As Web3 gains momentum and ushers in the era of decentralized applications and blockchain technology, developers are faced with new challenges in designing robust and scalable architectures. Service Oriented Architecture (SOA) is a proven architectural pattern that provides a solution for building modular, interoperable, and scalable systems. In this chapter, we explore SOA in general, its benefits and challenges, and discuss how this architecture pattern can be applied to Web3 applications.
W. Sarada, Pramod Kumar, G. Rekha, B. Aishwarya · 6 authors
The advances in the architecture of the new web and propelled by Web3 innovations are the major playground where the Internet is moving at a pace faster than we could imagine. It is towards that direction that this research seeks to examine the effectiveness of decentralised systems with emphasis on how Blockchains, Smart Contracts and Peer to Peer systems can revolutionalise the internet by offering more security, transparency and user ownership. Web3 technologies pin the inconvenience of Web2 as being too centralized, lacking in privacy, and problematic in terms of data ownership; Web3 can champion decentralized applications [or dApps] and smart contracts. Taking the key blockchain camps including Ethereum, Solana, and Polkadot into consideration, the study measures their effectiveness, operation capability, and security features. Success and failure rates of the decentralized architecture concept in response to problems affecting different sectors such as finance, healthcare, and digital ownership are measured by simulations as well as the case studies. Particular emphasis is created on such issues as scalability, legal requirements, and user acceptance. Application blockchains are audited by means of blockchain analytics tools and smart contract testing frameworks to identify the strengths and weaknesses of DApps in order to improve them. This research also points towards the issues that require focusing on the improvement of governance models, UX interfaces, and security frameworks in the Web3 sphere. By assessing the existing decentralized platforms and perform performance study, the research identifies the drawbacks and challenges of the blockchain platform and suggests probable solutions to tackle them. Thus, the study results indicate that decentralized web architectures as such have a rather high potential in the future, although the issues of scalability and usability will become the main factors to define their success.
In this research paper, we introduce a Kotlin application that assesses different security features on the Android SDK and executes them. The objectives are:1.Improving security of mobile phones—The most commonly used for m-payments; High-value targets, because they store substantial amount of personal information (especially financial details);2.Some of the available features include data obfuscation and anti-screenshot which is meant to be obedient with security guidelines set by RBI for financial apps.3.Zero-Knowledge Proof — enables the parties to verify facts about each other without sharing personal data and removes risks associated with unauthorized access or data breaches, significantly enhancing security for end-users.It is important to have this kind of initiative for any financial application that you develop, otherwise how can an app user trust your code and be sure it met all possible regulations?!
Ken Huang, Youwei Yang, Fan Zhang, Xi Chen · 5 authors
Chapter 4 examines the scaling of Web3 to support widespread adoption. It first discusses why scalability is crucial for Web3, enabling it to handle high transaction volumes and users such as centralized systems. Scalability refers to the ability to sustain performance amid growth. Key factors are number of users, response time, storage, transaction costs, and throughput. Scalability is challenging due to the blockchain trilemma of decentralization, security, and scalability. Solutions involve optimizations at the network layer (layer 0), blockchain layer (layer 1), and Off-chain layer (layer 2). Layer 0 focuses on data transfer, using protocols such as BloXroute. Layer 1 aims to improve the blockchain itself via methods like sharding or new consensus algorithms. Layer 2 leverages Off-chain processing via rollups, sidechains, and state channels. Each layer has trade-offs. Rollups bundle transactions Off-chain using zero-knowledge proofs or fraud proofs before validating On-chain. Sidechains process transactions externally to relieve the main chain’s load. State channels allow Off-chain transfers between participants. No single scaling approach fits all cases. A combination of solutions across layers tailored to the application offers the most potential.
In the context of Web3.0, the rapid pace of technological innovation has resulted in the emergence of novel computing paradigms. This is a natural result of the exponential growth of technology. Within the ecosystem of Web 3.0, the major emphasis of this research is on rethinking architecture and protocols in order to be ready for the revolution in edge computing. To improve the efficacy, security, and scalability of data processing and transmission, DECABI provides a dynamic edge computing architecture with integrated blockchain characteristics. The study accelerates data transfers without compromising their integrity by using dynamic resource allocation, encrypted data transmission, and a consensus protocol for edge computing (CPEC). The suggested method has much better performance than the alternatives. This exemplifies how the method has the ability to completely alter the way edge computing is carried out in the Web3.0 era. Countless simulations and exhaustive studies confirmed the existence of this option. This study lays the groundwork for a more stable and secure Web3.0 ecosystem, and it also makes a substantial contribution to the current conversation about the future of computer architectures and protocols.
This chapter is designed to help the readers build a solid foundation on Web3. The chapter is divided into three parts. The first part intends to build the conceptual foundation on Web3 – the primary qualities of Web3. The second part covers how Web3 fits into long-term technical and business evolutions. The third part delves into the core technology that enables Web3. This part is further divided into six parts – distributed systems, blockchains, smart contracts and tokens, blockchain economics, Ethereum, and Ethereum virtual machine.
The primary theme of the book is decentralization making this chapter one of the most important chapters in this book. This chapter delves into the concept of decentralization. The chapter is divided into nine parts. The first few parts discuss the concept of decentralization. Then the discussion turns to the governance of tech platforms and decentralized governance on Web3 platforms. The chapter ends with a few case studies on DAO-based governance on Web3 platforms.
The chapter delves into the details of Web3 architectures. The chapter is divided into three parts. The first part is conceptual and covers how Web3 systems are designed as networks contrasting the layered design of Web2 platforms. The second part discusses the elements of Web3 networks, and the third part covers the third-party elements that play very important roles in Web3 systems. This section is further divided into six parts and covers scaling solutions, oracles, privacy protocols, communication protocols, interoperability solutions, and a brief discussion on decentralized identity solutions.
Blockchain, as a decentralized distributed ledger technology, offers secure data exchange and reliable identity authentication for Internet of Things (IoT) devices, introducing new ideas for IoT development. Practical Byzantine Fault Tolerance (PBFT) is a widely used consensus algorithm that is well-suited for the IoT environment due to its low computing power requirements. However, the vast number of devices in the IoT presents a challenge. PBFT necessitates inter-node communication, which leads to decreased scalability as the number of devices grows. To overcome these IoT limitations, this paper proposes an improved PBFT algorithm based on reputation value. Nodes are evaluated and assigned levels according to their reputation values, with higher level nodes being chosen to engage in the consensus process, thereby minimizing the risk of malicious nodes participating. The primary node is unpredictably chosen from high-reputation nodes using random numbers. This approach also simplifies the consensus algorithm process and reduces communication complexity. Experimental findings indicate that the reputation value-based improved PBFT algorithm can diminish communication overhead and consensus delay.
The present study explores the field of decentralized oracles, paying specific attention to the Chainlink network. Additionally, the study includes the creation of a decentralized finance (DeFi) trader smart contract that integrates Chainlink's oracles and price feeds. Moreover, it is discussed how decentralized oracles play a crucial role in facilitating connectivity between blockchain systems and external data sources, thereby bolstering operational capabilities and broadening the scope of functionalities available to blockchain applications. The principal aim of this research is to illustrate the incorporation and application of decentralized oracles in practical settings, particularly by means of the construction of a DeFi trader smart contract. The purpose of this contract is to utilize Chainlink's dependable and secure price feeds for the implementation of essential trading operations, including the initiation and processing of purchase and sale transactions, as well as the management of limit orders. The utilization of reliable and promptly available market data from Chainlink's decentralized oracle network enables the smart contract to facilitate efficient and transparent trading activities. The primary elements of this study entail a comprehensive examination of Chainlink's complex architectural framework, consisting of decentralized oracle networks (DONs) that collate and authenticate data from various origins to safeguard the accuracy and integrity of the data. The research also examines pertinent security issues such as Sybil attacks, data manipulation, and node collusion, and delves into different strategies to mitigate these risks, including cryptographic proofs, multi-source data aggregation, and robust consensus mechanisms. In summary, this investigation highlights the importance of decentralized oracles in enhancing the functionalities of blockchain technology and DeFi applications. The results emphasize the need for extensive implementation and incorporation of decentralized oracles in order to guarantee the sustained progress and prosperity of blockchain ecosystems. This study offers a thorough and technical analysis of the architecture, security, and practical uses of Chainlink decentralized oracles, providing valuable perspectives for the advancement of financial innovations based on blockchain technology.
Warmayana I Gede Agus Krisna, Koki Hayashida, Hiroki Minegoshi, Nobuto Oka
To effectively utilize globally distributed materials data, we developed a prototype decentralized materials data management system. The secure, transparent, and efficient management of materials data was achieved using blockchain technology, smart contracts, non-fungible tokens (NFT), and interplanetary file system (IPFS) in Web3. The effectiveness of the prototype was also discussed in the case studies using performance data on materials used in environmental purification and rechargeable batteries.
Decentralized Finance (DeFi) has emerged as a contemporary competitive as well as complementary to traditional centralized finance systems. As of 23rd January 2024, per Defillama approximately USD 55 billion is the total value locked on the DeFi applications on all blockchains put together. A Byzantine Fault Tolerant (BFT) State Machine Replication (SMR) protocol, popularly known as the consensus protocol, is the central component of a blockchain. If forks are possible in a consensus protocol, they can be misused to carry out double spending attacks and can be catastrophic given high volumes of finance that are transacted on blockchains. Formal verification of the safety of consensus protocols is the golden standard for guaranteeing that forks are not possible. However, it is considered complex and challenging to do. This is reflected by the fact that not many complex consensus protocols are formally verified except for Tendermint and QBFT. We focus on Supra's Pipelined Moonshot consensus protocol. Similar to Tendermint's formal verification, we too model Pipelined Moonshot using IVy and formally prove that for all network sizes, as long as the number of Byzantine validators is less than one thirds, the protocol does not allow forks, thus proving that Pipelined Moonshot is safe and double spending cannot be done using forks. The IVy model and proof of safety is available on Github.
This paper presents, for the first time, the Mediterraneous protocol. It is designed to support the development of an Internet of digital services, owned by their creators, and consumed by users by presenting their decentralised digital identity and a proof of service purchase. Mediterraneous is Self-Sovereign Identity (SSI) native, integrating the SSI model at the core of its working principles to overcome the limitations resulting from using pseudonyms and centralised access control of existing Web3 solutions.
U ovom radu su istraženi mehanizmi koji osiguravaju i decentraliziraju blok-lanac mreže čiji se konsenzus postiže mehanizmom dokaza o zalogu (engl. Proof of Stake). Dan je pregled različitih načina na koji korisnici mogu sudjelovati validaciji mreže. Predstav- ljene su prednosti za korisnike koji sudjeluju, no i mane koje se pojavljuju prisutnošću većeg broja transakcija na mreži u jedinici vremena. Objašnjen je predložen pristup koji povezuje tehnologije skaliranja blok-lanac mreža i validacije uz analizu rezultata i pri- jedloge poboljšanja te decentralizirane aplikacije.
The rapid evolution of intelligent systems has led to the emergence of distributed artificial intelligence architectures where multiple agents collaborate to solve complex problems. However, enabling secure and trustworthy collaboration among distributed agents remains a major challenge due to issues related to data integrity, privacy, and trust management. Blockchain technology offers a decentralized and tamper-resistant infrastructure that can address these challenges by enabling transparent and secure coordination among intelligent agents. This paper proposes a blockchain-enabled distributed intelligence platform designed to support secure multi-agent collaboration across decentralized environments. The architecture integrates smart contracts, distributed ledgers, and machine learning agents to create a trusted computational ecosystem where agents can exchange data, validate actions, and coordinate decisions without relying on centralized authorities.
Blockchain technology is a decentralized, distributed ledger technology that allows digital information to be recorded, stored and shared securely and transparently. It is achieved through a network of computers that verify and record transactions, using cryptographic algorithms to ensure the integrity and security of the data. Blockchain technology was created in 2008 by Satoshi Nakamoto to record and verify transactions without a central authority. In 2014, Ethereum was introduced, allowing developers to create and deploy decentralized applications on top of the blockchain. Since then, blockchain technology has evolved and found new use cases in industries such as finance, supply chain management, healthcare, and voting systems. There are four types of blockchain: including public, private, hybrid, and consortium blockchains. Public blockchains are open networks that anyone can join and participate in, while private blockchains are closed networks that are only accessible to a select group of people or organizations. Hybrid blockchains combine the features of two or more types of blockchains. Consortium blockchains are a hybrid of public and private blockchains. The choice of which type to use will depend on the specific needs and goals of the project or application. Blockchain technology has a bright future ahead of it, with many of possible uses and room for innovation. Increased adoption, interoperability, scaling, decentralized finance, and environmental sustainability are a few of them. Ultimately, the development of new applications and use cases, growing adoption, and ongoing innovation will likely define the future of blockchain technology.