Stefan Pancari, Anik Rashid, Jason Zheng, Shirali Patel · 6 authors
Despite the lack of blockchain systems being utilized in modern IoT environments, the prevalence of blockchain technology is increasing, due to its high level of security and accountability. The integration of blockchain technology and access control in a decentralized system for smart home networks is a promising solution to this issue. This paper compares the implementation of attribute-based access control (ABAC) with two popular blockchain platforms, Ethereum and Hyperledger Fabric, for a smart home internet of things (IoT) environment. We present a comprehensive summary of access-control and blockchain-access-control methods, to provide the necessary background for this study. Additionally, we present an original ABAC smart contract for Ethereum, and the modification of a pre-existing Hyperledger Fabric ABAC smart contract, for this comparison. Through the simulation of both implementations, the advantages and limitations will be considered, to determine which is better suited for a smart home IoT environment.
Mochamad Heru Riza Chakim, Aliyah, M. Adhit Dwi Yuda, Rifqi Fahrudin · 5 authors
Voting is one of the methods used by humans to determine decisions in a case. Along with the development of technology, conventional voting also follows the transformation in the adaptation of the current digital era. There is an electronic version of this voting which is often called e-voting (electronic voting). Of course, the application of technology in voting will raise public opinion about concerns about maintaining network privacy and security in e-voting. Of course, security problems can be overcome with technology that is currently being utilized optimally in various fields of life, namely blockchain technology. In enhancing e-voting security, blockchain will be used in P2P networks. The application of the blockchain system in e-voting will produce a safe e-voting system so that it can reduce the percentage of forgery of votes in the e-voting system. Implementing a blockchain-based e-voting system will involve 3 elements, namely cryptography, software engineering theory, and voting theory. In realizing blockchain-based e-voting, several stages are needed. (1) vote counterfeiting is avoided by adjusting the voting recording model based on ledger technology, (2) in terms of authentication, this technology is equipped with elliptic curve cryptography (ECC) based user model design, (3) providing a model designed for voters to change their vote before the specified time limit. The integration of these three designs is an important requirement in the e-voting process, proving and verifying a blockchain-based e-voting system in a P2P network that has been designed on linux.
Electronic voting systems have the potential to improve the efficiency and accessibility of elections, but they also introduce unique challenges in terms of security, privacy, and voter anonymity. In this paper, we propose a secure and privacy-preserving voting system based on zero-knowledge proofs and homomorphic encryption. Our system ensures the integrity, confidentiality, and authenticity of votes while preserving the anonymity of voters. We present the system architecture, design, and implementation, along with a detailed analysis of the cryptographic techniques employed. The evaluation of our proposed system demonstrates its effectiveness, efficiency, and scalability, making it suitable for use in large-scale elections. This work contributes to the ongoing efforts to develop more secure, transparent, and accessible electronic voting systems for the future.
At the heart of the Crypto Code lies the blockchain technology. Blockchain is a decentralized and distributed ledger system that records transactions across a network of computers. It ensures transparency, security, and immutability, making it a suitable infrastructure for handling digital currencies. Each block in the chain contains a list of transactions, and these blocks are linked together in chronological order, creating a continuous and unalterable chain of information.
The development of an electronic voting system that would replace traditional election procedures is a research topic of great interest for many years. Blockchain technology could provide some guarantees and fulfill strong requirements for electronic voting platforms, such as transparency, immutability, and confidentiality. From time to time research is conducted to address problems in voting systems. Many research works attempt to implement secure and reliable voting systems, which address known security, anonymity, and fraud issues that might threaten such systems. This paper presents a proposal of a secure electronic voting system, the EtherVote, using the Ethereum Blockchain network that focuses deeply on the field of identification of eligible citizens. The proposed system will be entirely based on Blockchain without any central authority servers or databases, thus improving security, privacy, and election cost. Limitations, problems, and solutions are discussed, in order to make the proposed electronic voting system ideal and ready to use for national elections.
Arnab Mukherjee, Souvik Majumdar, Anup Kumar Kolya, S. Nandi
Within a modern democratic nation, elections play a significant role in the nation's functioning. However, with the existing infrastructure for conducting elections using Electronic Voting Systems (EVMs), many loopholes exist, which illegitimate entities might leverage to cast false votes or even tamper with the EVMs after the voting session is complete. The need of the hour is to introduce a robust, auditable, transparent, and tamper-proof e-voting system, enabling a more reliable and fair election process. To address such concerns, we propose a novel solution for blockchain-based e-voting, focusing on the security and privacy aspects of the e-voting process. We consider the security risks and loopholes and aim to preserve the anonymity of the voters while ensuring that illegitimate votes are properly handled. Additionally, we develop a prototype as a proof of concept using the Ethereum blockchain platform. Finally, we perform experiments to demonstrate the performance of the system.
Community detection is widely used in social networks to uncover groups of related vertices (nodes). In cryptocurrency transaction networks, community detection can help identify users that are most related to known illegal users. However, there are challenges in applying community detection in cryptocurrency transaction networks: (1) the use of pseudonymous addresses that are not directly linked to personal information make it difficult to interpret the detected communities; (2) on Bitcoin, a user usually owns multiple Bitcoin addresses, and nodes in transaction networks do not always represent users. Existing works on cluster analysis on Bitcoin transaction networks focus on addressing the later using different heuristics to cluster addresses that are controlled by the same user. This research focuses on illegal community detection containing one or more illegal Bitcoin addresses. We first investigate the structure of Bitcoin transaction networks and suitable community detection methods, then collect a set of illegal addresses and use them to label the detected communities. The results show that 0.06% of communities from daily transaction networks contain one or more illegal addresses when 2,313,344 illegal addresses are used to label the communities. The results also show that distance-based clustering methods and other methods depending on them, such as network representation learning, are not suitable for Bitcoin transaction networks while community quality optimization and label-propagation-based methods are the most suitable.
Block production in Bitcoin, often referred to as mining, is becoming increasingly industrialized. Many nodes in the network are represented by registered business entities. The concept of Bitcoin as a Service is also pushing the industry to become more customer oriented. Services such as transaction validation, transaction status query or notification, and blockchain data indexing are in high demand among blockchain application providers and users. As service providers, nodes need to distinguish themselves from others and be identifiable. In this article, we introduce an efficient self-established identity system, called Miner ID, to enable nodes to be publicly identifiable. It is based on economic investment and active participation in the blockchain network. Moreover, Miner ID is optional for nodes, and it does not affect the consensus mechanism of the network. We explore use cases including instant transaction confirmation, blockchain attestation, public key infrastructure, and token recovery. Miner ID can also be used for secure communication with applications, services, users and peers.
Voting mechanisms play a crucial role in decentralized governance of blockchain systems. Liquid democracy, also known as delegative voting, allows voters to vote directly or delegate their voting power to others, thereby contributing to the resolution of problems such as low voter turnout. In recent years, liquid democracy has been widely adopted by Delegated-Proof-of-Stake (DPoS) blockchains and implemented successfully on platforms with millions of users. However, little is known regarding the characteristics and actual effectiveness of liquid democracy in decentralized governance. This paper explored for the first time the practical implementation of liquid democracy in DPoS blockchain systems. Using actual data collected from two major DPoS blockchains, EOS and Steem, our study compared and evaluated the participation of different types of users of DPoS blockchain systems in liquid democracy, as well as extracting and analyzing the delegation chains and networks formed during the process of liquid democracy within the systems. We believe that the findings of this paper will contribute to further studies on the design and implementation of liquid democracy and other voting mechanisms in decentralized governance.
Web3Recommend is a decentralized Social Recommender System implementation that enables Web3 Platforms on Android to generate recommendations that balance trust and relevance. Generating recommendations in decentralized networks is a non-trivial problem because these networks lack a global perspective due to the absence of a central authority. Further, decentralized networks are prone to Sybil Attacks in which a single malicious user can generate multiple fake or Sybil identities. Web3Recommend relies on a novel graph-based content recommendation design inspired by GraphJet, a recommendation system used in Twitter enhanced with MeritRank, a decentralized reputation scheme that provides Sybil-resistance to the system. By adding MeritRank's decay parameters to the vanilla Social Recommender Systems' personalized SALSA graph algorithm, we can provide theoretical guarantees against Sybil Attacks in the generated recommendations. Similar to GraphJet, we focus on generating real-time recommendations by only acting on recent interactions in the social network, allowing us to cater temporally contextual recommendations while keeping a tight bound on the memory usage in resource-constrained devices, allowing for a seamless user experience. As a proof-of-concept, we integrate our system with MusicDAO, an open-source Web3 music-sharing platform, to generate personalized, real-time recommendations. Thus, we provide the first Sybil-resistant Social Recommender System, allowing real-time recommendations beyond classic user-based collaborative filtering. The system is also rigorously tested with extensive unit and integration tests. Further, our experiments demonstrate the trust-relevance balance of recommendations against multiple adversarial strategies in a test network generated using data from real music platforms.
Eko Yanuarso Budi, Cahyo Prihantoro, Nicolaus Euclides Wahyu Nugroho
Electronic voting (e-voting) merupakan salah satu jenis sistem voting yang prosesnya berjalan dengan sistem elektronik. E-voting dikembangkan untuk menjadi alternatif lain voting tradisional negara demokrasi. Di Indonesia sistem pemilihan menggunakan e-voting mulai diterapkan pada skala desa. Dengan adanya perancangan website e-voting menggunakan smart contract blockchain Polygon bertujuan agar melengkapi sistem yang sudah ada terutama keamanan, transparansi dan meningkatkan kepercayaan masyarakat dalam proses pemilihan. Penerapan blockchain pada masa sekarang masih dibilang awal tentunya membutuhkan pengembangan dan improvisasi. Mekanisme yang ditawarkan pada penelitian ini adalah penggunaan smart contract voting yang artinya proses voting berjalan diatas jaringan blockchain. Pemilih akan mendapatkan Non-Fungible Token setelah voting sukses sebagai bukti telah memilih.
Stanisław Barański, Julian Szymański, Higinio Mora
Abstract Lawyers, laboratories, auditors, and banks often need access to sensitive personal data to provide services such as genetic testing, paternity testing, STD testing, credit scoring, or legal advice. Processing such data exposes both service providers (SPs) and users to privacy risks: SPs risk violating laws like the General Data Protection Regulation (GDPR) and the Consumer Protection Act (CPA), while users risk losing their privacy. We observe that personal data is often only needed for logistical purposes like payment or communication and could be provided anonymously if suitable methods existed. To address this, we present a solution that enables services to be delivered without collecting personal data. Our protocol combines anonymous payment methods (e.g., cash, privacy-preserving cryptocurrencies), blockchain for fairness, and distributed content-addressable storage networks to deliver results. Compared to existing approaches, our protocol achieves anonymity under weaker assumptions, supports the transfer of physical materials and conflict resolution, and eliminates the need for customer interaction with a trusted arbiter in conflict-free cases-making it more practical. We analyze the protocol’s fairness and implement a prototype using Ethereum as a message board, Monero for anonymous payments, and Powergate (IPFS/Filecoin) as a decentralized storage solution.
The Internet of Energy (IoE) is a distributed paradigm that leverages smart networks and distributed system technologies to enable decentralized energy systems. In contrast to the traditional centralized energy systems, distributed Energy Internet systems comprise multiple components and communication requirements that demand innovative technologies for decentralization, reliability, efficiency, and security. Recent advances in blockchain architectures, smart contracts, and distributed federated learning technologies have opened up new opportunities for realizing decentralized Energy Internet services. In this paper, we present a comprehensive analysis and classification of state-of-the-art solutions that employ blockchain, smart contracts, and federated learning for the IoE domains. Specifically, we identify four representative system models and discuss their key aspects. These models demonstrate the diverse ways in which blockchain, smart contracts, and federated learning can be integrated to support the main domains of IoE, namely distributed energy trading and sharing, smart microgrid energy networks, and electric and connected vehicle management. Furthermore, we provide a detailed comparison of the different levels of decentralization, the advantages of federated learning, and the benefits of using blockchain for the IoE systems. Additionally, we identify open issues and areas for future research for integrating federated learning and blockchain in the Internet of Energy domains.
Isaac David, Liyi Zhou, Kaihua Qin, Dawn Song · 6 authors
We investigate the feasibility of employing large language models (LLMs) for conducting the security audit of smart contracts, a traditionally time-consuming and costly process. Our research focuses on the optimization of prompt engineering for enhanced security analysis, and we evaluate the performance and accuracy of LLMs using a benchmark dataset comprising 52 Decentralized Finance (DeFi) smart contracts that have previously been compromised. Our findings reveal that, when applied to vulnerable contracts, both GPT-4 and Claude models correctly identify the vulnerability type in 40% of the cases. However, these models also demonstrate a high false positive rate, necessitating continued involvement from manual auditors. The LLMs tested outperform a random model by 20% in terms of F1-score. To ensure the integrity of our study, we conduct mutation testing on five newly developed and ostensibly secure smart contracts, into which we manually insert two and 15 vulnerabilities each. This testing yielded a remarkable best-case 78.7% true positive rate for the GPT-4-32k model. We tested both, asking the models to perform a binary classification on whether a contract is vulnerable, and a non-binary prompt. We also examined the influence of model temperature variations and context length on the LLM's performance. Despite the potential for many further enhancements, this work lays the groundwork for a more efficient and economical approach to smart contract security audits.
Many existing anonymous parking payment schemes lack high efficiency and flexibility. For instance, the calculation and communication costs involved in payment may linearly increase with the payment amount. In this paper, we propose an anonymous payment system (dubbed AnoPay) for vehicle parking, which leverages updatable attribute-based anonymous credentials and efficient zero-knowledge proof (ZKP) to achieve user anonymity and constant overhead for parking fee payment. To further improve the efficiency, we design a secure parking fee aggregation protocol based on linear homomorphic encryption to aggregate parking transactions, where the amount of each parking transaction is hidden and the privacy of the parking lot in terms of its revenue is guaranteed. AnoPay achieves both unlinkability and accountability, malicious payments can be efficiently traced when it is necessary. We provide a security model and rigorous proof for each security property of AnoPay. Extensive experiments and comparisons demonstrate the efficiency and practicality of the system.
Dominic Grandjean, Lioba Heimbach, Roger Wattenhofer
In September 2022, Ethereum transitioned from Proof-of-Work (PoW) to Proof-of-Stake (PoS) during "the merge" - making it the largest PoS cryptocurrency in terms of market capitalization. With this work, we present a comprehensive measurement study of the current state of the Ethereum PoS consensus layer on the beacon chain. We perform a longitudinal study of the history of the beacon chain. Our work finds that all dips in network participation are caused by network upgrades, issues with major consensus clients, or issues with service operators controlling a large number of validators. Further, our longitudinal staking power decentralization analysis reveals that Ethereum PoS fairs similarly to its PoW counterpart in terms of decentralization and exhibits the immense impact of (liquid) staking services on staking power decentralization. Finally, we highlight the heightened security concerns in Ethereum PoS caused by high degrees of centralization.
To address the problems that current studies for enhancing network accountability based on IPv6 addresses do not support cross-Autonomous Systems (AS) or restrict threatener behaviors, a distributed IPv6 Address Traceback and Threatener Restriction Mechanism (ATTRM6) based on smart contract is proposed. Tracing servers of each AS form a blockchain and invoke smart contract functions to store address information of different ASes on the blockchain. When IPv6 address traceback is needed across ASes, the traceback server of a specific AS reads addresses information stored on the blockchain to identify the threatener. Considering the restriction scheme for threatener associated with IPv6 addresses, and proposing a Punishment-Forgiveness Policy (PFP) to dynamically adjust the reputation of threatener, and store restricted threatener and their reputation on the blockchain, thus providing data support to each AS to take restriction measures. Compared with information sharing based on a centralized database, the ATTRM6 mechanism can accomplish more reliable sharing. Experimental results show that the ATTRM6 mechanism has low overhead and can effectively perform IPv6 address traceback and threatener restriction.
Blockchain is a decentralized, distributed ledger that records transactions between two parties. A blockchain-based software system is a new and innovative approach to software engineering that uses blockchain technology. This approach has several advantages over traditional software engineering approaches, including improved security and transparency. The most common software engineering approaches are waterfall, agile and hybrid models. Each of these has its strengths and weakness. A blockchain-based system has the advantage of being more secure and transparent than any of these approaches. It also can track changes more accurately, which can improve quality control. Blockchain technologies have incredible potential but also have some problems. One problem is security and privacy issues, which brings into question the resilience of existing security and trust mechanisms. The distributed application (dApp) framework for the proposed electronic voting system is built with the help of blockchain technology in this proposal. As a result, fewer crimes has committed against sensitive data during the electoral process because of immutability, transparency and privacy. Ganache, Metamask and hashing algorithms are used to develop the dApp. The paper's strengths lie in its ability to create and analyze threat models for blockchain-enabled-electronic voting systems and to identify the types of threats using Microsoft STRIDE.
Viji Rajendran, A. Jasrotia, Ghulam Murtaza, Rohit Sharma
Any democracy must have an open voting<br> process that satisfies the needs of the populace to give the<br> appropriate individual the power. Additionally, the<br> traditional voting systems currently in use have<br> significant flaws and lack security and transparency. It<br> has long been difficult to create a safe electronic voting<br> system that provides the transparency and flexibility<br> provided by electronic systems, while maintaining the<br> fairness and privacy of present voting schemes. In this<br> project, we assess a blockchain-based implementation of<br> distributed electronic voting systems. It addresses some<br> of the well-known blockchain frameworks with the aim<br> of building a blockchain-based electronic voting system<br> and presents a novel electronic voting system based on<br> blockchain that tackles some of the shortcomings in<br> existing systems. In particular, we evaluate the potential<br> of distributed ledger technologies through the<br> description of a case study; namely, the process of an<br> election, and the implementation of a blockchain-based<br> application, which improves the security and decreases<br> the cost of hosting a nationwide election.
The rapid digital revolution in recent decades has resulted in an overwhelming amount of information, particularly in the realm of modern education systems and related materials. This phenomenon, often referred to as information overload, necessitates the development of educational systems that can effectively search, classify, and categorize this vast amount of available information. Of utmost importance for such educational information systems is the safeguarding of personal data, which refers to information that can identify an individual or their family. School records, for example, contain various types of personal data such as the individual’s name, address, contact details, disciplinary history, as well as their grades and progress checks. Even if individuals choose to make this data public, it remains inherently personal. Another category of data involves more sensitive topics such as student biometrics (e.g. fingerprints, photographs), religious beliefs, health information (e.g. allergies), or dietary restrictions, which may imply religious or health-related aspects. Processing data in this category can pose risks to individuals; hence, strict rules and appropriate consent are necessary to ensure their protection. To address these challenges, this research paper proposes a zero-knowledge proof intelligent recommendation system designed to protect students’ data privacy in the digital age. The proposed method incorporates an Intelligent Recommendation System (IRS) that utilizes an optimized version of the Matrix Factorization technique, calculated as an Eulerian Walk chart. Furthermore, the Schnorr Zero-Knowledge Proof format, based on the discrete logarithm problem, ensures the privacy of personal data during message exchange between educational entities.
With the recent hype around the Metaverse and NFTs, Web3 is getting more and more popular. The goal of Web3 is to decentralize the web via decentralized applications. Wallets play a crucial role as they act as an interface between these applications and the user. Wallets such as MetaMask are being used by millions of users nowadays. Unfortunately, Web3 is often advertised as more secure and private. However, decentralized applications as well as wallets are based on traditional technologies, which are not designed with privacy of users in mind. In this paper, we analyze the privacy implications that Web3 technologies such as decentralized applications and wallets have on users. To this end, we build a framework that measures exposure of wallet information. First, we study whether information about installed wallets is being used to track users online. We analyze the top 100K websites and find evidence of 1,325 websites running scripts that probe whether users have wallets installed in their browser. Second, we measure whether decentralized applications and wallets leak the user's unique wallet address to third-parties. We intercept the traffic of 616 decentralized applications and 100 wallets and find over 2000 leaks across 211 applications and more than 300 leaks across 13 wallets. Our study shows that Web3 poses a threat to users' privacy and requires new designs towards more privacy-aware wallet architectures.
With natural language processing as an important research direction in deep learning, the problems of text similarity calculation, natural language inference, question and answer systems, and information retrieval can be regarded as text matching applications for different data and scenarios. Secure matching computation of text string patterns can solve the privacy protection problem in the fields of biological sequence analysis, keyword search, and database query. In this paper, we propose an Intelligent Semi-Honest System (ISHS) for secret matching against malicious adversaries. Firstly, a secure computation protocol based on the semi-honest model is designed for the secret matching of text strings, which adopts a new digital encoding method and an ECC encryption algorithm and can provide a solution for honest participants. The text string matching protocol under the malicious model which uses the cut-and-choose method and zero-knowledge proof is designed for resisting malicious behaviors that may be committed by malicious participants in the semi-honest protocol. The correctness and security of the protocol are analyzed, which is more efficient and has practical value compared with the existing algorithms. The secure text matching has important engineering applications.
Hao Xu, Yunqing Sun, Zihao Li, Yao Sun · 6 authors
Web3 brings an emerging outlook for the value of decentralization, boosting the decentralized infrastructure. People can benefit from Web3, facilitated by the advances in distributed ledger technology, to read, write and own web content, services and applications more freely without revealing their real identities. Although the features and merits of Web3 have been widely discussed, the network architecture of Web3 and how to achieve complete decentralization considering law compliance in Web3 are still unclear. Here, we propose a perspective of Web3 architecture, deController, consisting of underlay and overlay network as Web3 infrastructures to underpin services and applications. The functions of underlay and overlay and their interactions are illustrated. Meanwhile, the security and privacy of Web3 are analyzed based on a novel design of three-tier identities cooperating with deController. Furthermore, the impacts of laws on privacy and cyber sovereignty to achieve Web3 are discussed.
Ring signcryption with no group administrator satisfies the decentralization and blockchain anonymity. In this article, we construct new lattice-based ring signcryption scheme suitable for consortium blockchain (CB-LRSCS), in which the smart contract controls the process of signcryption and unsigncryption to make the system be fair and reliable. CB-LRSCS can protect the user privacy by reducing the connection between blockchain and user information, and it satisfies the reliability in ethereum environment. CB-LRSCS also has the characteristics of high efficiency, anti-quantum, anti-forgery, confidentiality and unconditional anonymity, and it can be applied in the electronic finance system.