Multiple Blockchains Research Articles

A secure interoperable method for electronic health records exchange on cross platform blockchain network

An Electronic Health Record (EHR) store essential and sensitive patient's medical information. Since health information is highly confidential data, it should be accessible with the consent of the patient. Blockchain based EHR management system offers improvised privacy and patient-centric approach. EHR management systems are available with multiple blockchain platforms. Generally, EHRs are maintained at several independent blockchain platforms. EHR management systems should be capable of securely exchange data on cross platform blockchain network. The interoperability in such blockchain platforms should facilitate seamless cross-chain interaction and information exchange. This article proposes a method that facilitates secure EHR exchange on Ethereum and Hyperledger fabric network using hepatitis dataset. The key contributions of the proposed method include:•Hash lock based interoperable cross-chain method for EHR exchange across Ethereum and Hyperledger fabric.•Additional security to the EHR is ensured by partitioning EHR as on-chain (blockchain platform) and off-chain InterPlanetary File System (IPFS)•Secure Password Authentication-Based Key Exchange (SPAKE) based session management for EHR exchange across two parties.The proposed patient centric method is validated to ensures the successful exchange of patient EHR across Ethereum and Hyperledger fabric.

Leveraging Blockchain Interoperability for Interdependent Networks

With the rapid emergence of technologies, coupling interdependent consumer electronics networks have become imperative to enable information exchange, holistic data analysis, and effective decision-making techniques. While interdependent networks can discover crucial information through intuitive understanding and efficient data-driven algorithms, it is crucial to leverage secure and effective data exchange among the underlying networks of consumer electronics. Blockchain comes into play when it requires ensuring trustless communication and data exchange amongst multiple interdependent networks. Blockchain interoperability is evolving and gaining widespread popularity in industry and research due to its ability to exchange data among multiple blockchains. This paper presents Divide-LeapChain, a next-generation efficient and effective interoperable blockchain framework for interdependent networks of heterogeneous consumer electronics devices. The Divide-LeapChain addresses the critical issues of intra- and inter-blockchain communication, including spatial and temporal uncertainties in data traversal, exchange, validation, and cross-chain swaps. It promises significant drops-off in verification steps without weakening blockchain integrity, which extends the possibilities to apply blockchain applications on heterogeneous embedded consumer Internet-of-Things (IoT) devices.

A secure dynamic cross-chain decentralized data consistency verification model

The continuous increase in the number of transactions is exerting significant pressure on the storage capacity of blockchains. By storing data on multiple blockchains and interacting with each other with cross-chain technology, the storage pressure can be relieved to a large degree. Nevertheless, the feature of immutability may impede the further development of blockchains, e.g., some expired identity information cannot be updated due to immutability. The decentralized chameleon hash function can resolve the issue while ensuring the feature of decentralization. Unfortunately, how to ensure the consistency of dynamic data updating in cross-chain interaction is still a question worth considering. In this paper, we propose a dynamic cross-chain decentralized data consistency verification (DCCV) model, in which we adopt an audit chain and design a dynamic Merkle hash tree to guarantee the consistency of dynamic data updating between the source chain and the target chain. In addition, in order to enhance the relevance of calculations across different smart contracts and improve audit efficiency, we propose a way to develop cross-chain smart contracts collaboratively. Moreover, Cosi protocol and multi-signcryption are utilized to ensure the security and privacy of cross-chain data transmission. Finally, theoretical and experimental analysis demonstrates that DCCV can achieve dynamic data consistency verification in the process of cross-chain interaction.

Enhancing Trustworthiness and Interoperability of Electronic Voting Systems through Blockchain Bridges

Decentralized applications leveraging blockchain technology are gaining widespread adoption within the decentralized applications ecosystem. Interoperability, a fundamental concept facilitating seamless data and processing power exchange across diverse blockchain networks, is paramount in this context. The primary objective of this paper is to explore the transformative potential of "blockchain bridges" in facilitating secure and transparent electronic voting processes across multiple blockchain networks. The study employs a comprehensive analysis of various approaches, including atomic exchanges, sidechains, cross-chain bridges, token wrappers, and interledger protocols. The selection of a specific method is guided by the unique requirements and privacy considerations of the electronic voting use case. The application of two distinct blockchains serves as a practical demonstration, illustrating the principles of blockchain bridges in real-world scenarios. The research reveals that blockchain bridges not only streamline the exchange of data between diverse blockchain networks but also establish a dual decentralization paradigm. This paradigm enables the creation of openly maintained, purpose-specific, decentralized ledgers for electronic voting. The integration of blockchain bridges significantly reduces the risk of fraud, instilling greater confidence in the accuracy of election results. Thus, by presenting a comprehensive array of approaches and emphasizing their practical application, this research contributes to advancing the understanding and implementation of blockchain technology in the critical domain of electronic voting. Doi: 10.28991/HIJ-2023-04-04-04 Full Text: PDF

Unveiling the Landscape of Smart Contract Vulnerabilities: A Detailed Examination and Codification of Vulnerabilities in Prominent Blockchains

With the rise in using immature smart contract programming languages to build a decentralized application, more vulnerabilities have been introduced to the Blockchain and were the main reasons behind critical financial losses. Moreover, the immutability of Blockchain technology makes deployed smart contracts unfixable for the whole life of the Blockchain itself. The lack of complete and up-to-date resources that explain those vulnerabilities in detail has also contributed to increasing the number of vulnerabilities in Blockchain. In addition, the lack of a standardized nomination of the existing vulnerabilities has made redundant research and made developers more confused. Therefore, in this paper, we propose the most complete list of smart contract vulnerabilities that exist in the most popular Blockchains with a detailed explanation of each one of them. In addition, we propose a new codification system that facilitates the communication of those vulnerabilities Moreover, the discussed list of vulnerabilities covers multiple Blockchain and could be used for even future built Blockchains.

A Green Supply Chain Management Strategy for E-Commerce Based on Multiple Blockchain Technology

Abstract In this paper, firstly, the e-commerce green supply chain management strategy of multivariate blockchain is explored, and digital assets are traded on the e-commerce supply chain platform through the information anchoring model. Secondly, the Diffie-Hellman algorithm is used to generate the key, the AES algorithm is used to encrypt the information, and the account data, transaction data and IoT data, are stored in three independent chains. Finally, the selection strategies of different e-commerce sales models and the green supply chain management strategies of e-commerce platforms are visually analyzed through numerical arithmetic examples. The results show that when E 0 = 10, it is optimized by the ecological R&D efforts of supply chain members. When E 0 = 50, the greenness of the product is decreasing. When it finally tends to the steady state, E ∞ C > E ∞ BR > E ∞ MR. The three green supply chain management models proposed in this study are conducive to enhancing consumer utility and in line with the sustainable development strategy.

Replacing IOT Hub with Multiple Block chain for IOT Data Aggregation and Predicting Land Sliding Through Machine Learning Technique

The IoT devices in remote areas are very much vulnerable. The data collecting hub is not secured for recent attacks. The data transferred is attacked before reaching the server. In the existing system, the blockchain is used for data aggregation. The data is secured by this technique but the cost of performing this is very high. In the proposed system the data aggregation is done by using multiple block chains which increase performance as well as the security provided. After receiving the data, the land sliding is predicted with heuristics. The device energy will be consumed very low when compared to the existing system. Security will be high by using multiple chains. The overload of mining and cryptography will be avoided.

Devising a method for rapid data retrieval using explorers for blockchain analysis

The object of this study is blockchain explorers and their usefulness in efficiently gathering data for blockchain network analysis. The process of blockchain analysis typically involves deploying and synchronizing a blockchain node, which requires significant computational resources and time for synchronization. Analyzing multiple blockchain networks simultaneously demands substantial effort and requires even greater costs. The developed method involves utilizing publicly accessible blockchain explorers, which allows for rapid data retrieval with minimal computational resources for further analysis. Additionally, obtaining supplementary information from blockchain explorers provides valuable details that may be inaccessible using traditional data retrieval methods. The efficiency of the proposed method was verified through the development of a prototype system. Data was collected for 14 specified blockchain networks to analyze smart contracts within these networks. Information about accounts (including balance statistics) was gathered, smart contracts were identified among the accounts, data on existing tokens owned by smart contracts was obtained, and bytecode and source code (where available) of contracts were collected and decompiled. The process took nearly 24 hours on a cloud computing machine with minimal configuration. Based on the collected data, an example smart contract was analyzed to demonstrate the completeness of the process. The results of this research minimize computational resource expenses and allow for a simplified and rapid data gathering process without manual configuration, enabling researchers and analysts to concentrate on subsequent stages of analysis

Exploring Blockchains Interoperability: A Systematic Survey

The next-generation blockchain ecosystem is expected to integrate both homogeneous and heterogeneous distributed ledgers. These systems require operations across multiple blockchains to enrich advanced functionalities for future applications. However, the development of blockchain interoperability involves much more complexity regarding the variety of underlying architectures. Guaranteeing the properties of ACID (Atomicity, Consistency, Isolation, Durability) across diverse blockchain systems remains challenging. To clear the fog, this article accordingly provides a comprehensive review of the current progress of blockchain interoperability. We explore the general principles and procedures for interoperable blockchain systems to highlight their design commons. Then, we survey practical instances and compare state-of-the-art systems to present their unique features between distinct solutions. Finally, we discuss critical challenges and point out potential research directions. We believe our work can provide an intuitive guideline for newcomers and also promote rapid development in terms of blockchain interoperability.

Antitrust Economics of Cryptocurrency Mining

Abstract The development of blockchain-based applications, to date mostly virtual currencies, touches many areas of law and economics. The most well-known applications of public blockchains rely on Proof of Work as a consensus mechanism in which miners compete to solve a cryptographic puzzle. We argue that economic tools for market definition may be adapted to delineate relevant cryptocurrency mining markets. Antitrust law can help to prevent network attacks and exclusion of transactions with lower fees by large miners. When multiple blockchains are part of the same market, the role of network effects in securing the leading position of more established cryptocurrencies can potentially lead to exclusionary behaviour.

Financial Transaction Management for NGO using Block Chain

Non-governmental organizations or NGOs, are primarily nonprofit groups, and a large portion of them are supported by members of NGO and public donations. The credibility of an NGO is substantially enhanced and donor confidence is greatly increased by maintaining transparency regarding how donations are used. Donor organizations provide funding to non-governmental organizations(NGOs) in developing various initiatives such as economic development, women’s empowerment, promoting education, responding to calamities and natural disasters. Due to some NGOs’ involvement in the misuse of funds, some donor agencies cease to have faith in NGOs method of operation. This system is decentralized, not owned or operated by a single person or organization but rather shared among users. We have developed a blockchain-based Donation System capable of decentralizing the resources used by a given organization. The user may create any new organization and others will be allowed to donate money in the organization. As a result, the public become the true owners of the resources, and the charity fund system as a whole becomes more transparent. Blockchain technology and distributed ledgers can reduce operational costs and bring us closer to real-time transactions between financial institutions. System uses cross chain protocol for reliably exchanging information without third party in a multiple Blockchain system

VM-Studio: A Universal Crosschain Smart Contract Verification and Execution Scheme

Blockchain interoperability promotes value delivery, application expansion, and ecological compatibility across heterogeneous blockchain systems. However, the contract framework and virtual machine construction in these systems are significantly different, and crosschaining becomes a challenging issue for system universality and compatibility. Starting from this problem, in this study, we propose VM-Studio, a crosschain smart contract verification and execution scheme to migrate the virtual machines (VMs) from the origin blockchain to the target blockchain. In our scheme, the migrated VMs are loaded as independent components enclosed in containers. We also design a unified system schedule to enable VM-Studio to allocate transactions into different containers. Loaded with origin blockchain VMs, these containers can accordingly solve crosschain transaction execution and smart contract verification. We implement VM-Studio and evaluate the transaction execution performance in the origin environment with multiple blockchains and the container environment. Experiment results demonstrate that VM-Studio achieves broad universality without compromising the execution performance of original blockchain transactions.

Atomic cross-chain swaps with improved space, time and local time complexities

An effective atomic cross-chain swap protocol is introduced by Herlihy [Herlihy, 2018] as a distributed coordination protocol in order to exchange assets across multiple blockchains among multiple untrusted parties. The atomic cross-chain swap protocol guarantees; (1) if all parties conform to the protocol, then all assets are exchanged among the parties, (2) even if some parties or coalitions of parties deviate from the protocol, no party conforming to the protocol suffers a loss, and (3) no coalition has an incentive to deviate from the protocol. Herlihy [Herlihy, 2018] invented this protocol by using hashed timelock contracts.A cross-chain swap is modeled as a directed graph D=(V,A). Vertex set V denotes a set of parties and arc set A denotes a set of proposed asset transfers. Let Δ be time enough for a party to publish a contract on any of the blockchains, or to change the state of a contract and for the other party to detect the change. The space complexity of the protocol is O(|A|2). The local time complexity of the protocol is O(|V|⋅|L|), where L is a feedback vertex set computed by the protocol. We propose a new atomic cross-chain swap protocol which uses only signature information and improves the space complexity to O(|A|⋅|V|) and the local time complexity to O(|V|). Moreover, if all parties conform to our protocol, our proposed protocol improves the time complexity from O(|V|Δ) to O(Δ).

Applying Social Network Analysis to Model and Handle a Cross-Blockchain Ecosystem

In recent years, the huge growth in the number and variety of blockchains has prompted researchers to investigate the cross-blockchain scenario. In this setting, multiple blockchains coexist, and wallets can exchange data and money from one blockchain to another. The effective and efficient management of a cross-blockchain ecosystem is an open problem. This paper aims to address it by exploiting the potential of Social Network Analysis. This general objective is declined into a set of activities. First, a social network-based model is proposed to represent such a scenario. Then, a multi-dimensional and multi-view framework is presented, which uses such a model to handle a cross-blockchain scenario. Such a framework allows all the results found in the past research on Social Network Analysis to be applied to the cross-blockchain ecosystem. Afterwards, this framework is used to extract insights and knowledge patterns concerning the behavior of several categories of wallets in a cross-blockchain scenario. To verify the goodness of the proposed framework, it is applied on a real dataset derived from Multichain, in order to identify various user categories and their “modus operandi”. Finally, a new centrality measure is proposed, which identifies the most significant wallets in the ecosytem. This measure considers several viewpoints, each of which addresses a specific aspect that may make a wallet more or less central in the cross-blockchain scenario.

Study on the Power Data Assets and Trading System Design of Blockchain

The sensitive data such as electric power data suffer from the easily abuse in the traditional centralized data trading system. To solve this problem, the blockchain-based power data’s capitalization and trading system were proposed in this study. Given the trust for blockchain technology, this work established a multi-party trusty network between multiple parties in the distributed ledger with cryptographic algorithms, and distributed multi-party consensus protocol. The system development with Hyperledger’s consortium blockchain framework Fabric made the power data safe, transparent and immutable. The local development environment for testing included a operating system MAC OS 10.14.6, six-core CPU 3.0 GHz, RAM 16 GB. A single machine is configured with multiple block chain network nodes, an ordering node, and two organizations Org0 and Org1, each of which has two nodes Peer0 and Peer1, and adopts the Solo consensus mechanism. The experimental results show that the system run well in the integrated test, satisfied the design requirements, and had low maintenance costs and improved security. Compared with the traditional data trading system, the blockchain-based power data’s capitalization and trading system demonstrated the comprehensive functionality and security advantages in the study.

HyperMaze: Towards Privacy-Preserving and Scalable Permissioned Blockchain

Blockchain systems face two emergent problems, namely scalability and privacy, each of which has been addressed independently. However, how to achieve privacy and scalability simultaneously remains a challenging problem for blockchains. In this article, we propose a privacy-preserving and scalable permissioned blockchain system called HyperMaze employing the zero knowledge proof technique and a hierarchical system architecture. It gains scalability by adopting a hierarchy of multiple blockchains that processes transactions in parallel. We design an <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">ID-based dual-balance account model</i> where an identity-based account is associated with two types of balances–a plaintext balance and a private (zero-knowledge) balance. Furthermore, we design a two-phase cross-chain transaction mechanism (2PXT) to achieve transaction privacy for both intra-chain and cross-chain transactions. We rigorously formulate a security model for HyperMaze under the universal composability framework, and then provide a simulation-based security proof. A prototype of HyperMaze is implemented and a series of experiments are conducted over up to 2,600 nodes to evaluate its performance. The experimental results show that a 4-level, (7,10)-threshold, 6-ary HyperMaze system can reach 19,440 TPS and the transaction confirmation latency is only 9.5 seconds. To our best knowledge, HyperMaze is the first high-throughput privacy-preserving blockchain whose throughput is over 19,000 TPS.

TRacer: Scalable Graph-Based Transaction Tracing for Account-Based Blockchain Trading Systems

Security incidents such as scams and hacks have become a major threat to the health of the blockchain ecosystem, resulting in billions of dollars in losses to blockchain users each year. To reveal the real-world entities behind pseudonymous blockchain accounts and recover stolen funds from massive transaction data, much effort has recently been put into tracing illicit financial flows in blockchain by academia and industry. However, most of the current blockchain fund tracing methods are heuristics and taint analysis methods that are designed on the basis of expert experience and specific events, which have limitations in terms of universality, effectiveness and efficiency. This paper models blockchain transaction records as a transaction graph and tackles blockchain transaction tracing as a graph search task. To achieve efficient and effective tracing of fund transfers on the transaction graphs, we propose a scalable transaction tracing tool, TRacer, which to the best of our knowledge is the <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">first</i> intelligent transaction tracing tool that is generalized to multiple account-based blockchain platforms and can handle complex transaction behavior in decentralized finance (DeFi). Particularly, we tackle the transaction tracing task via a subgraph searching approach which employ a novel ranking method to infer the relevance between accounts during the graph search process in the multi-relational blockchain transaction graph. Theoretical analysis and experimental results on datasets from multiple blockchain platforms demonstrate that TRacer can efficiently perform the transaction tracing task at a lower cost and achieve better tracing results than existing methods or even expert manual audits.

Securing Medical Datasets using Block Chain Technology

Medical data sets are crucial in modern healthcare as they provide valuable information that helps in advancing medical research, improving patient care, and making informed decisions. They allow healthcare providers to track patient health records, evaluate treatments and outcomes, and identify trends and patterns in disease diagnosis and management. Additionally, medical data sets are used for training AI models that can assist healthcare professionals in diagnosing and treating diseases, providing accurate and timely patient care, and reducing medical errors.&#x0D; In recent years millions of patient records have already been compromised due to data thefts in the healthcare industry ranging from patient’s private health data to hospitals accounting, reporting, DNA structures etc. are all being taken. Blockchain technology, which is regarded as a trustworthy way to maintain documents, could be utilized to protect full security and confidentiality. This approach would not only safeguard patient data but also due to decentralized structure of a technology it also lead to more efficient treatment of patients as information would be readily and instantly available. Therefore, proper implementation of the blockchain system will not only increase individual service but also remove the need for external parties to provide security.&#x0D; The study proposed a model that would unites almost all of the leading healthcare providers, by combining all Electronic Health Record (EHR) system including hospitals, clinics, and specialized Laboratories as well. MedBloc, a blockchain-based safe EHR system that offers accessibility, safety, and protection is described. It allows both patients and healthcare professionals to view and exchange medical records, by extracting important ideas that can be used to create multiple blockchain systems and vulnerability scanning that address security flaws. This article also presents blockchain vulnerability management options by analyzing some assaults upon blockchain, including hashing, connectivity, smart contract and privacy breach cyberattacks. It has been proven difficult as a result of trustworthy attack analysis techniques. Therefore, we explore the blockchain's user privacy in this paper and consider potential fixes. We systematically divide the three kinds of blockchain attack strategies, then mentioned the associated attack and defense techniques that rely on such divisions.

A Blockchain-Based Data Sharing System with Enhanced Auditability

Cloud platforms provide a low-cost and convenient way for users to share data. One important issue of cloud-based data sharing systems is how to prevent the sensitive information contained in users’ data from being disclosed. Existing studies often utilize cryptographic primitives, such as attribute-based encryption and proxy re-encryption, to protect data privacy. These approaches generally rely on a centralized server which may cause a single point of failure problem. Blockchain is known for its ability to solve such a problem. Some blockchain-based approaches have been proposed to realize privacy-preserving data sharing. However, these approaches did not fully explore the auditability provided by the blockchain. The dishonest cloud server can share data with a requester without notifying the data owner or being logged by the blockchain. In this paper, we propose a blockchain-based privacy-preserving data sharing system with enhanced auditability. The proposed system follows the idea of hybrid encryption to protect data privacy. The data to be shared are encrypted with a symmetric key, and the symmetric key is encrypted with a joint public key which is the sum of multiple blockchain nodes’ public keys. Only if a data requester is authorized, the blockchain nodes will be triggered to execute a verifiable key switch protocol. By using the output of the protocol, the data requester can get the plaintext of the symmetric key. The blockchain nodes participate in both the authorization process and the key switch process, which means the behavior of the data requester is witnessed by multi-parties and is auditable. We implement the proposed system on Hyperledger Fabric. The simulation results show that the performance overhead is acceptable.

A blockchain based access control scheme with hidden policy and attribute

Attribute-based access control, which can provide fine-grained and flexible privacy protection, is widely used in practice. Traditional attribute-based access control schemes require the intervention of a trusted third party, which will cause single point of failure. Due to its decentralized nature, blockchain is now considered as a promising way to solve the above issue. The basic idea of existing blockchain-based access control schemes is to code the access policy into a smart contract. However, the transparency of the blockchain makes it easier for the adversary to explore the public information to launch a privacy attack. In this paper, we propose an attribute-based access control scheme which benefits from the smart contract technology while ensuring the privacy of attributes and policies. An additive homomorphic cryptosystem is utilized to encrypt attributes and access policies. The scheme uses multiple blockchain nodes to collectively decrypt the data, and uses zero-knowledge proof technology to ensure the correctness of the decryption result. Therefore, the smart contract is able to make the authorization decision without actually seeing attributes or policies. We have implemented the proposed access control scheme on Hyperledger Fabric. Simulation results show that the computation overhead introduced by encryption/decryption and zero-knowledge proof is reasonable.