Public Ledger Research Articles

Tri-op redactable blockchains with block modification, removal, and insertion

In distributed computations and cryptography, it is desirable to record events on a public ledger, such that later alterations are computationally infeasible. An implementation of this idea is called blockchain, which is a distributed protocol that allows the creation of an immutable ledger. While such an idea is very appealing, the ledger may be contaminated with incorrect, illegal, or even dangerous data, and everyone running the blockchain protocol has no option but to store and propagate the unwanted data. The ledger is bloated over time, and it is not possible to remove redundant information. Finally, missing data cannot be inserted later. Redactable blockchains were invented to allow the ledger to be mutated in a controlled manner. To date, redactable blockchains support at most two types of redactions: block modification and removal. The next logical step is to support block insertions. However, we show that this seemingly innocuous enhancement renders all previous constructs insecure. We put forward a model for blockchains supporting all three redaction operations and construct a blockchain that is provably secure under this formal definition.

Artificial Intelligence-Powered Blockchains for Cardiovascular Medicine

Clinical databases, particularly those composed of big data, face growing security challenges. Blockchain, the open, decentralized, distributed public ledger technology powering cryptocurrency, records transactions securely without the need for third-party verification. In the health care setting, decentralized blockchain networks offer a secure interoperable gateway for clinical research and practice data. Here, we discuss recent advances and potential future directions for the application of blockchain and its integration with artificial intelligence (AI) in cardiovascular medicine. We first review the basic underlying concepts of this technology and contextualise it within the spectrum of current, well known applications. We then consider specific applications for cardiovascular medicine and research in areas such as high-throughput gene sequencing, wearable technologies, and clinical trials. We then evaluate current challenges to effective implementation and future directions. We also summarise the health care applications that can be realised by combining decentralized blockchain computing platforms (for data security) and AI computing (for data analytics). By leveraging high-performance computing and AI capable of securely managing large and rapidly expanding medical databases, blockchain incorporation can provide clinically meaningful predictions, help advance research methodology (eg, via robust AI-blockchain decentralized clinical trials), and provide virtual tools in clinical practice (eg, telehealth, sensory-based technologies, wearable medical devices). Integrating AI and blockchain approaches synergistically amplifies the strengths of both technologies to create novel solutions to serve the objective of providing precision cardiovascular medicine.

블록체인 기반의 사용자 관리 가능한 증명서 시스템

Credentials are one of the most important things to prove oneself in modern society. As the world goes digital, credentials change its form from paper to digital. However, digital data are easy to be forged and to be duplicated. To make digital data secure, cryptographic digital signature is the key technology ensuring its authenticity and integrity. And it is an inevitable choice for secure credential management systems. Recently blockchain has been raised as another key technology to guarantee data transparency. It is a decentralized and public ledger of transactions that anyone can participate and execute programs called smart contract. In this paper, we propose a credential management system based on Ethereum blockchain. This system provides users with a means both to manage their credentials by themselves and to prove their credentials without the issuer. We implemented its prototype on Ethereum, and analyzed the proposed system compared to previous systems.

RiceChain: secure and traceable rice supply chain framework using blockchain technology.

The increasing number of rice product safety issues and the potential for contamination have established an enormous need for an effective strategy for the traceability of the rice supply chain. Tracing the origins of a rice product from raw materials to end customers is very complex and costly. Existing food supply chain methods (for example, rice) do not provide a scalable and cost-effective means of agricultural food supply. Besides, consumers lack the capability and resources required to check or report on the quality of agricultural goods in terms of defects or contamination. Consequently, customers are forced to decide whether to utilize or discard the goods. However, blockchain is an innovative framework capable of offering a transformative solution for the traceability of agricultural products and food supply chains. The aim of this paper is to propose a framework capable of tracking and monitoring all interactions and transactions between all stakeholders in the rice chain ecosystem through smart contracts. The model incorporates a system for customer satisfaction feedback, which enables all stakeholders to get up-to-date information on product quality, enabling them to make more informed supply chain decisions. Each transaction is documented and stored in the public ledger of the blockchain. The proposed framework provides a safe, efficient, reliable, and effective way to monitor and track rice products safety and quality especially during product purchasing. The security and performance analysis results shows that the proposed framework outperform the benchmark techniques in terms of cost-effectiveness, security and scalability with low computational overhead.

A Project-Based Approach for Learning Blockchain Technology

Blockchain technology (BT) is gaining popularity, and there have been increasing papers on blockchain and education, particularly on how to use blockchains in education. However, as a public ledger which is shared and agreed on by all users in a distributed network, blockchain technology involves unconventional thinking, and learning BT could be challenging for college students. In this paper, we present a project-based learning (PBL) approach for effective education of BT at college level. We first explain why PBL is suitable for BT education and discuss various issues should be considered for project-based learning on blockchain technology. We then discuss several different ways of doing this and offer our suggestions. We present case studies which we have developed, that can provide useful guidelines to students and beginners who are interested in BT.

Blockchain-based Transparency Framework for Privacy Preserving Third-party Services

Increasingly, information systems rely on computational, storage, and network resources deployed in third-party facilities such as cloud centers and edge nodes. Such an approach further exacerbates cybersecurity concerns constantly raised by numerous incidents of security and privacy attacks resulting in data leakage and identity theft, among others. These have, in turn, forced the creation of stricter security and privacy-related regulations and have eroded the trust in cyberspace. In particular, security-related services and infrastructures, such as Certificate Authorities (CAs) that provide digital certificate services and Third-Party Authorities (TPAs) that provide cryptographic key services, are critical components for establishing trust in crypto-based privacy-preserving applications and services. To address such trust issues, various transparency frameworks and approaches have been recently proposed in the literature. This paper proposes TAB framework that provides transparency and trustworthiness of third-party authority and third-party facilities using blockchain techniques for emerging crypto-based privacy-preserving applications. TAB employs the Ethereum blockchain as the underlying public ledger and also includes a novel smart contract to automate accountability with an incentive mechanism that motivates users to participate in auditing, and punishes unintentional or malicious behaviors. We implement TAB and show through experimental evaluation in the Ethereum official test network, Rinkeby, that the framework is efficient. We also formally show the security guarantee provided by TAB, and analyze the privacy guarantee and trustworthiness it provides.

Blockchain-Based Identity Management System and Self-Sovereign Identity Ecosystem: A Comprehensive Survey

Identity Management System (IDMS) refers to how users or individuals are identified and authorized to use organizational systems and services. Since traditional identity management and authentication systems rely heavily on a trusted central authority, they cannot mitigate the effects of single points of failure. As a decentralized and distributed public ledger in a peer-to- peer (P2P) network, Blockchain (BC) technology has garnered a considerable amount of attention in the field of IDMS in recent years. Through Self-Sovereign Identity (SSI), users can have full authority over their digital identity. Successful implementation of a BC-based IDMS can significantly increase the degree of privacy and security of a user’s SSI. However, the integration of BC-based IMDS to provide a user with SSI is still an unorganized area of research in its early stages of development. This article presents an extensive literature review of state-of-the-art academic publications as well as commercial market offerings regarding the applicability of BC-based SSI solutions. It also provides a detailed preliminary regarding the building blocks of blockchain technology and a progressive roadmap of IDMS solutions. In order to develop an effective BC-based IDMS solution that focuses on securing a user’s SSI, this article outline five essential components of a BC-based IDMS: authentication, integrity, privacy, trust, and simplicity. Furthermore, we perform a security analysis that outlines several types of adversarial threats that can cause potential damage to the BC-based IDMS. We identify and discuss associated issues and challenges by analyzing several notable BC-based IDMS solutions in academic literature. We also highlight potential research gaps and provide future research scope.

A Review: Consensus Algorithms on Blockchain

Blockchain is a distributed public ledger that keeps track of all transactions that have ever taken place in the system. As a distributed ledger, a consensus mechanism is required to ensure all the transaction functions properly. In order to reach a consensus, it is critical to emphasize the importance of performance and efficiency. The use of the right consensus algorithm will significantly improve the efficiency of a blockchain application. This paper reviewed several types of consensus algorithms used in blockchain and discusses the idea of a new consensus algorithm that can improve the performance of consortium blockchain.

Function Virtualization Can Play a Great Role in Blockchain Consensus

Bitcoin introduced a cryptocurrency as a form of public ledger consequently that turned into a most popular security technology, Blockchain. Its integrated mining technology lies the key security mechanism. The system allows forming a pool mining group to solve a particular job and share their revenues to their CPU usage while one of them successfully mines a block. To mine a block, a cryptographic puzzle should be solved, which requires significant compute resources that cause huge energy consumption. On the other hand, recent statistics show that low computational energy-restricted Internet of Things (IoT) devices are increasing exponentially. Although it has low energy and limited computation power, it is large in quantity when it is integrated. So we focus on a stochastic geometry theory, which resolves the issue of block mining computation via utilizing multiple mobile IoT devices, given that these IoT devices are Computation Capable Nodes (CCNs). To further normalize this issue, we propose an efficient mathematical solution that uses smart coordination of Virtual Network Functions (VNFs) for IoT devices to enable their CPU usage efficiently. At the same time, the work and credit point distribution policy is smartly handled through virtual pool mining. The proposal renders Network Function Virtualization technology to configure VNF, and Service Function Chain technology is utilized to enable the network flow of such VNFs. New algorithms are presented to solve multiple issues like node discovery, computation offloading, and work credit point distribution. Our goal is to minimize energy consumption within the given time constraint. Implementation results show that although virtual functions for block mining require extensive computations in IoT devices, dividing computation work into small fractions called tasks embedded with VNF, and offloading them to nearby CCNs, tend to minimize the cost and energy consumption of individual shared miners. The overall mining process is proved efficient and faster.

A Survey of Blockchain From the Perspectives of Architecture and Applications

The increasing need for organizations to keep a high level of synchronization around the world and the coming of new advancements are pushing increasingly more to move decision-making and operational power from the focus of associations to their edges. The blockchain could be the critical innovation to roll out this improvement conceivable. A blockchain is essentially a distributed database of records or public ledger of all transactions or digital events that have been executed and shared among participating parties. Blockchain is pleased with the fact that it provides high satisfaction and a trust bond to its users. Data immutability, decentralization, anonymity, auditability, and transparency are the main features that make blockchain an attractive technology. This paper presents a study of blockchain technology to provide a comprehensive analysis that includes types, architecture, components, characteristics, and applications of blockchain.

Opinion mining towards blockchain technology adoption for accessing digital library resources

PurposeBlockchain technology is a distributed and decentralized public digital ledger, which is employed to save dynamic transaction data and static records across several computers so that each record could not be modified retroactively without the collusion of the network and alteration of all subsequent blocks. Recently, it has become immensely popular in digital resource sharing in different research areas such as healthcare, smart cities, cryptocurrency and libraries. Since the current eLibrary systems are vulnerable to issues such as unauthorized access, plagiarism, etc., there is a lack of access control system that can efficiently address these issues.Design/methodology/approachThe authors designed a conceptual model for evaluating the users' intention in the use of blockchain-based digital libraries, which can facilitate the resource organization and provide additional security to interactive processes between users. To conduct our survey, the authors devised and shared two versions, English and Chinese, among 298 participants. Moreover, 7 PhD students participated in the pre-testing of the questioner design. The authors analyzed the demographic data using the Jamovi software and SmartPLS in order to generate the path modeling.FindingsThis study revealed that blockchain technology adaption in eLibraries is essential for enhancing the quality of services, infrastructure and resources for libraries. The study’s results show that optimism, informativeness, perceived usefulness, perceived ease of use, attitude and intention to use blockchain technology for accessing digital resources in libraries.Originality/valueThis study contributes to the adoption of blockchain technology in the digital library. To the best of the authors’ knowledge, this work is the first empirical attempt to provide a new perspective of developing digital libraries based on security policies. This model shows the underpinning knowledge to manage digital resources, which can facilitate the design phases and enhance the management costs in eLibraries.

Integration of Self Sovereign Identity in Security Systems

Transactions over the internet have increased rapidly and so is the need to prove one’s identity and have a secured system to keep records. To overcome identity theft and fraud cases, Self-Sovereign Identity (SSI) was introduced which gives the user complete control over their identity on the internet. Self-Sovereign Identity eliminates the centralized authority and brings Zero-knowledge proof concepts into account to help in easy transactions over the internet. It avoids revealing unnecessary information and correlation attacks. Self-Sovereign Identity, on top of blockchain public ledger features, provides an extra security layer to the system that can be used to monitor the entries in confidential places. This research paper describes a software module, that we have developed, to grant verifiable credentials to users. These credentials, on verification, can grant entry into any security system with which the module is integrated. The module utilizes the facilities provided by Hyperledger Indy and Hyperledger Aries for the creation of verifiable credentials and subsequent verification in a secure manner.

Design of mutual trust between the IoT nodes using adaptive network-based fuzzy inference system in edge computing systems

Advancements in Internet of Things (IoT) enabled faster collection of data and its analysis in valuable form to provide essential services for the stake holders. However, most of the nodes contributes to privacy and security issues due to its distributed nature, network scale and resource scarcity towards IoT networks. In this paper, use blockchain model that provides a strong counter measure for the data protection and enables optimal support of IoT via its distributed nature. However, it consumes enormous consumption of energy that verifies the data blocks and creates severe restriction over the resource-constrained nature of IoT device. Also, it may pose serious threat that exposes the user privacy onto public ledger system and leads to data alterations. Hence, the study advances the security using mutual trust between the IoT nodes to support the data verification at blocks and data privacy of stakeholders in real-time. The ANFIS model computes the degree of mutual trust between the IoT nodes and at the same time it enables the blockchains to participate in trust based estimation. The simulation is carried out to evaluate the proposed model with other state-of-art methods. The test results shows that the proposed method achieves higher degree of trust and high privacy of packets than other methods.

Distributed Hybrid Double-Spending Attack Prevention Mechanism for Proof-of-Work and Proof-of-Stake Blockchain Consensuses

Blockchain technology is a sustainable technology that offers a high level of security for many industrial applications. Blockchain has numerous benefits, such as decentralisation, immutability and tamper-proofing. Blockchain is composed of two processes, namely, mining (the process of adding a new block or transaction to the global public ledger created by the previous block) and validation (the process of validating the new block added). Several consensus protocols have been introduced to validate blockchain transactions, Proof-of-Work (PoW) and Proof-of-Stake (PoS), which are crucial to cryptocurrencies, such as Bitcoin. However, these consensus protocols are vulnerable to double-spending attacks. Amongst these attacks, the 51% attack is the most prominent because it involves forking a blockchain to conduct double spending. Many attempts have been made to solve this issue, and examples include delayed proof-of-work (PoW) and several Byzantine fault tolerance mechanisms. These attempts, however, suffer from delay issues and unsorted block sequences. This study proposes a hybrid algorithm that combines PoS and PoW mechanisms to provide a fair mining reward to the miner/validator by conducting forking to combine PoW and PoS consensuses. As demonstrated by the experimental results, the proposed algorithm can reduce the possibility of intruders performing double mining because it requires achieving 100% dominance in the network, which is impossible.

P2P Payment using Blockchain Technology

A Blockchain protocol operates on top of the Internet, on a P2P network of computers that all run the protocol and hold an identical copy of the ledger of transactions, enabling P2P value transactions without a middleman though machine consensus. The concept of Blockchain first came to fame in October 2008, as part of a proposal for Bitcoin, with the aim to create P2P money without banks. Bitcoin introduced a novel solution to the age-old human problem of trust. The underlying blockchain technology allows us to trust the outputs of the system without trusting any actor within it. People and institutions who do not know or trust each other, reside in different countries, are subject to different jurisdictions, and who have no legally binding agreements with each other, can now interact over the Internet without the need for trusted third parties like banks, Internet platforms, or other types of clearing institutions. Ideas around cryptographically secured P2P networks have been discussed in the academic environment in different evolutionary stages, mostly in theoretical papers, since the 1980s. “Proof-of-Work” is the consensus mechanism that enables distributed control over the ledger. It is based on a combination of economic incentives and cryptography. Blockchain is a shared, trusted, public ledger of transactions, that everyone can inspect but which no single user controls. It is a distributed database that maintains a continuously growing list of transaction data records, cryptographically secured from tampering and revision.

Blockchain-based Trusty Buyer Coalition Scheme Using A Group Signature

Without trust, buyers may not join a coalition. Despite the tremendous need for trustworthy relationships in buyer coalitions, no current buyer coalition scheme explicitly tackles confidence issues with blockchain technology. This study proposes an algorithmic design, the blockchain-based trusty buyer coalition scheme, to satisfy the trust requirement among different actors while forming the coalition. All activities forming a coalition through a decentralized public ledger can be explicitly examined. Consequently, the proposed algorithm can ensure anonymity within a community, resulting in trusting relationships. Furthermore, the proposed algorithm can ensure correctness and accountability by recognizing misbehavior and enforcing alternative forms of punishment. Additionally, the discovered algorithm can be applied to mobile commerce applications.

SkillsChain: A Decentralized Application That Uses Educational Robotics and Blockchain to Disrupt the Educational Process.

Our epoch is continuously disrupted by the rapid technological advances in various scientific domains that aim to drive forward the Fourth Industrial Revolution. This disruption resulted in the introduction of fields that present advanced ways to train students as well as ways to secure the exchange of data and guarantee the integrity of those data. In this paper, a decentralized application (dApp), namely skillsChain, is introduced that utilizes Blockchain in educational robotics to securely track the development of students’ skills so as to be transferable beyond the confines of the academic world. This work outlines a state-of-the-art architecture in which educational robotics can directly execute transactions on a public ledger when certain requirements are met without the need of educators. In addition, it allows students to safely exchange their skills’ records with third parties. The proposed application was designed and deployed on a public distributed ledger and the final results present its efficacy.

Privacy-enhancing distributed protocol for data aggregation based on blockchain and homomorphic encryption

The recent increase in reported incidents of security breaches compromising users' privacy call into question the current centralized model in which third-parties collect and control massive amounts of personal data. Blockchain has demonstrated that trusted and auditable computing is possible using a decentralized network of peers accompanied by a public ledger. Furthermore, Homomorphic Encryption (HE) guarantees confidentiality not only on the computation but also on the transmission, and storage processes. The synergy between Blockchain and HE is rapidly increasing in the computing environment.This research proposes a privacy-enhancing distributed and secure protocol for data aggregation backboned by Blockchain and HE technologies. Blockchain acts as a distributed ledger which facilitates efficient data aggregation through a Smart Contract. On the top, HE will be used for data encryption allowing private aggregation operations. The theoretical description, potential applications, a suggested implementation and a performance analysis are presented to validate the proposed solution.

On Prices of Privacy Coins and Bitcoin

Since the inauguration of cryptocurrencies, Bitcoin has been under pressure from competing tokens. As Bitcoin is a public open ledger blockchain coin, it has its weaknesses in privacy and anonymity. In the recent decade numerous coins have been initiated as privacy coins, which try to tackle these weaknesses. This research compares mostly mature privacy coins to Bitcoin, and comparison is made from a price perspective. It seems that Bitcoin is leading privacy coins in price terms, and correlation is typically high and positive. From the earlier crypto market peak of 2017–18, only a very small number of coins are showing positive returns in 2021. It is typical that many privacy coins have lost substantial amounts of their value (ranging 80–90%) or that they do not exist anymore at all. Only Horizen and Monero have shown long-term sustainability in their value; however, their price changes follow that of Bitcoin very closely. The role of privacy coins in the future remains as an open issue.

Next-Generation Digital Voting System

Building an electronic voting system that meets legislators' legal criteria has been a long-standing challenge. Distributed ledger technologies are a revolutionary innovation in the field of information technology. Blockchain technologies can be used in an unlimited number of ways to profit from sharing economies. All current electronic voting methods have a fundamental design problem. They're designed to be tightly controlled, which means there seems to be one source in charge of the code base, database, and system outputs, as well as the monitoring tools to ensure the results are accurate. Due to the lack of an independently verified output, these centralized systems struggle to gain the trustworthiness necessary by voters, either restricting voter participation or casting doubt on the election's declared results. The study seeks to use the cryptographic ledger as a safe transaction database to establish an immutable, verifiable, and secure online voting system. Voters will be able to independently audit the inclusion of their vote, as well in the election's overall outcome, using this public ledger, while knowing that the results cannot be altered due to the immutability of the Blockchain.