Alevtina Dubovitskaya, Zhigang Xu, Samuel Ryu, Michael Schumacher · 5 authors
Electronic medical records (EMRs) are critical, highly sensitive private information in healthcare, and need to be frequently shared among peers. Blockchain provides a shared, immutable and transparent history of all the transactions to build applications with trust, accountability and transparency. This provides a unique opportunity to develop a secure and trustable EMR data management and sharing system using blockchain. In this paper, we present our perspectives on blockchain based healthcare data management, in particular, for EMR data sharing between healthcare providers and for research studies. We propose a framework on managing and sharing EMR data for cancer patient care. In collaboration with Stony Brook University Hospital, we implemented our framework in a prototype that ensures privacy, security, availability, and fine-grained access control over EMR data. The proposed work can significantly reduce the turnaround time for EMR sharing, improve decision making for medical care, and reduce the overall cost.
Summary This paper investigates alternative configurations of different blockchain architectures that can be used for gathering and processing transactions in a range of different settings, including accounting, auditing, supply chain and other types of transaction information. Although there has been substantial focus on the peer‐to‐peer and public versions of blockchain, this paper focuses primarily on cloud‐based and private configuration versions of blockchains and investigates use configurations, advantages and limitations as firms bring blockchain‐based market mechanisms into their organizations. In addition, this paper investigates some emerging issues associated with blockchain use in consortium settings. Finally, this paper relates some proposed uses of blockchain for transaction processing to other technologies, such as data warehouses and databases.
Current construction engineering management suffers numerous challenges in terms of the trust, information sharing, and process automation. Blockchain which is a decentralised transaction and data management technology, has attracted increasing interests from both academic and industrial aspects since 2008. However, most of the existing research and practices are focused on the blockchain itself (i.e. technical challenges and limitations) or its applications in the finance service sector (i.e. Bitcoin). This paper aims to investigate the potential of applying blockchain technology in the construction sector. Three types of blockchain-enabled applications are proposed to improve the current processes of contract management, supply chain management, and equipment leasing, respectively. Challenges of blockchain implementation are also discussed in this paper.
The authors describe blockchain's fundamental concepts, provide perspectives on its challenges and opportunities, and trace its origins from the Bitcoin digital cash system to recent applications.
The dissemination of patients' medical records results in diverse risks to patients' privacy as malicious activities on these records cause severe damage to the reputation, finances, and so on of all parties related directly or indirectly to the data. Current methods to effectively manage and protect medical records have been proved to be insufficient. In this paper, we propose MeDShare, a system that addresses the issue of medical data sharing among medical big data custodians in a trust-less environment. The system is blockchain-based and provides data provenance, auditing, and control for shared medical data in cloud repositories among big data entities. MeDShare monitors entities that access data for malicious use from a data custodian system. In MeDShare, data transitions and sharing from one entity to the other, along with all actions performed on the MeDShare system, are recorded in a tamper-proof manner. The design employs smart contracts and an access control mechanism to effectively track the behavior of the data and revoke access to offending entities on detection of violation of permissions on data. The performance of MeDShare is comparable to current cutting edge solutions to data sharing among cloud service providers. By implementing MeDShare, cloud service providers and other data guardians will be able to achieve data provenance and auditing while sharing medical data with entities such as research and medical institutions with minimal risk to data privacy.
Jan 1, 2017·Proceedings of the ... Annual Hawaii International Conference on System Sciences/Proceedings of the Annual Hawaii International Conference on System Sciences
Digital supply chain integration is becoming \ increasingly dynamic. Access to customer demand \ needs to be shared effectively, and product and service \ deliveries must be tracked to provide visibility in the \ supply chain. Business process integration is based on \ standards and reference architectures, which should \ offer end-to-end integration of product data. \ Companies operating in supply chains establish \ process and data integration through the specialized \ intermediate companies, whose role is to establish \ interoperability by mapping and integrating companyspecific \ data for various organizations and systems. \ This has typically caused high integration costs, and \ diffusion is slow. This paper investigates the \ requirements and functionalities of supply chain \ integration. Cloud integration can be expected to offer \ a cost-effective business model for interoperable \ digital supply chains. We explain how supply chain \ integration through the blockchain technology can \ achieve disruptive transformation in digital supply \ chains and networks.
Sinclair Davidson, Primavera De Filippi, Jason Potts
Abstract Blockchains are a new digital technology that combines peer-to-peer network computing and cryptography to create an immutable decentralised public ledger. Where the ledger records money, a blockchain is a cryptocurrency, such as Bitcoin; but ledger entries can record any data structure, including property titles, identity and certification, contracts, and so on. We argue that the economics of blockchains extend beyond analysis of a new general purpose technology and its disruptive Schumpeterian consequences to the broader idea that blockchains are an institutional technology. We consider several examples of blockchain-based economic coordination and governance. We claim that blockchains are an instance of institutional evolution.
Zhetao Li, Jiawen Kang, Rong Yu, Dongdong Ye · 6 authors
In industrial Internet of things (IIoT), peer-to-peer (P2P) energy trading ubiquitously takes place in various scenarios, e.g., microgrids, energy harvesting networks, and vehicle-to-grid networks. However, there are common security and privacy challenges caused by untrusted and nontransparent energy markets in these scenarios. To address the security challenges, we exploit the consortium blockchain technology to propose a secure energy trading system named energy blockchain. This energy blockchain can be widely used in general scenarios of P2P energy trading getting rid of a trusted intermediary. Besides, to reduce the transaction limitation resulted from transaction confirmation delays on the energy blockchain, we propose a credit-based payment scheme to support fast and frequent energy trading. An optimal pricing strategy using Stackelberg game for credit-based loans is also proposed. Security analysis and numerical results based on a real dataset illustrate that the proposed energy blockchain and credit-based payment scheme are secure and efficient in IIoT.
This column evaluates blockchain's roles in strengthening security in the Internet of Things (IoT). Key underlying mechanisms related to the blockchain-IoT security nexus are covered. From a security standpoint, the article highlights how blockchain-based solutions could be, in many aspects, superior to the current IoT ecosystem, which relies mainly on centralized cloud servers. Using practical applications and real-world examples, the article argues that blockchain's decentralized nature is likely to result in a low susceptibility to manipulation and forgery by malicious participants. Special consideration is given to how blockchain-based identity and access management systems can address some of the key challenges associated with IoT security. The column provides a detailed analysis and description of blockchain's roles in tracking the sources of insecurity in supply chains related to IoT devices. Using blockchain, it is also possible to contain an IoT security breach in a targeted way after it is discovered. The column also discusses and evaluates initiatives of organizations, interorganizational networks, and industries on the frontlines of blockchain.
Blockchain technology provides decentralized consensus and potentially enlarges the contracting space through smart contracts. Meanwhile, generating decentralized consensus entails distributing information that necessarily alters the informational environment. We analyze how decentralization relates to consensus quality and how the quintessential features of blockchain remold the landscape of competition. Smart contracts can mitigate informational asymmetry and improve welfare and consumer surplus through enhanced entry and competition, yet distributing information during consensus generation may encourage greater collusion. In general, blockchains sustain market equilibria with a wider range of economic outcomes. We further discuss the implications for antitrust policies targeted at blockchain applications. Received May 31, 2017; editorial decision May 29, 2018 by Editor Itay Goldstein.
With the increase in the use of virtual currencies across the globe, the security of Bitcoin wallets has become a serious concern for the Bitcoin community. The developers are trying to implement concrete security solutions in Bitcoin wallets to ensure that no vulnerability gets exploited. However, a large number of known, as well as zero-day attacks, are launched on the Bitcoin wallets on a daily basis, resulting in a loss of bitcoins. In this regard, this paper presents a security analysis of existing Android wallets. We demonstrate how the implemented security practices can be bypassed by malicious entities, causing financial loss to Bitcoin users. As a countermeasure, we present a smart card based authentication scheme which will protect the users from all of the identified attacks.
Distributed ledger technology (DLT) that stores data (usually immutable and sequenced transaction records) in a decentralized way through cryptography and consensus algorithms. The first widely recognized implementation of the blockchain took place in 2009 on the Bitcoin public blockchain. Since then, other types of blockchain have been developed for a wide range of applications and features built on common principles such as decentralization, encryption, consensus, and immutability. In particular, blockchain technology is most widely used in transaction settlement and digital currency banks and the financial sector, as well as in supply chain applications that help participants solve problems quickly and efficiently. Other use cases continue to be developed. As a form of information management, blockchain and related DLTs offer advantages over traditional databases and may help develop certain new technologies such as the Internet of Things. Blockchain regulation is currently restricted at the international and federal levels, but state-level legislation provides support and awareness of aspects of blockchain technology. Most of the current regulations are in the form of self-regulation by blockchain developers and related communities, but many challenges and risks such as data privacy and security need to be addressed in the near future.
Blockchains are distributed ledgers. Distributed ledgers replace centralized ledgers. Distributed ledgers use nodes—computers—to record, share, and synchronize transactions in their electronic ledgers. The paper examines how blockchain data is arranged into blocks and how an append-only mode chain links them. Distributed ledger technology (DLT) encrypts and consensuses immutable and sequential transaction records. Bitcoin pioneered blockchain. Since then, many blockchains with decentralization, encryption, consensus, and immutability have been developed for diverse uses. Blockchain technology is most typically used in transaction settlement, digital currency banks, and supply chain applications to solve problems quickly. The study examines how blockchain and DLTs might improve information management and build new technologies like the Internet of Things. The study shows how legal issues encourage blockchain technology despite limited international and federal restrictions. However, data privacy and security must be addressed immediately.
Bitcoin was introduced in a self-published paper by Satoshi Nakamoto in October, 2008[1, 2]. Bitcoin is a decentralized system which requires no central authority. In recent years, bitcoin has become increasingly accepted and used in many fields in place of physical cash. Bitcoin is a peer-to-peer network of nodes that distribute and record transactions [3]. Bitcoin transaction is a statement that Player 1 (address 1) would like to transfer some bitcoin values to Player 2 (address 2), signed by Player 1 by his private key. Transactions are verified by network nodes and confirmed in a public distributed ledger called the block chain. The block chain consists of a series of blocks in which each block contains the hashed value of subsequent block. Every bitcoin block contains a set of verified transactions that are collected from the bitcoin broadcast network. It is assumed that the majority of nodes in the bitcoin network are honest. This makes the verification done by the nodes is correct with high probability. More technically, bitcoin is an electronic-cash system based on cryptographic algorithms.
Open access
Advanced Steganography and Watermarking Techniques
In this paper, we identify a new form of attack, called the Balance attack, against proof-of-work blockchain systems. The novelty of this attack consists of delaying network communications between multiple subgroups of nodes with balanced mining power. Our theoretical analysis captures the precise tradeoff between the network delay and the mining power of the attacker needed to double spend in Ethereum with high probability. We quantify our probabilistic analysis with statistics taken from the R3 consortium, and show that a single machine needs 20 minutes to attack the consortium. Finally, we run an Ethereum private chain in a distributed system with similar settings as R3 to demonstrate the feasibility of the approach, and discuss the application of the Balance attack to Bitcoin. Our results clearly confirm that main proof-of-work blockchain protocols can be badly suited for consortium blockchains.
Досліджено, що технологія Blockchain має значний потенціал застосування у різних сферах діяльності, однак найбільш перспективою сферою застосування цієї технології є Інтернет речей і кіберфізичні системи. Технологія Blockchain пропонує рішення проблеми безпеки і конфіденційності у середовищі Інтернет речей, забезпечуючи новий обчислювальний шар, де дані можуть бути безпечно оброблені та проаналізовані, залишаючись приватним. Розкрито потенційні переваги та виділено проблеми, які потрібно вирішити для ефективного використання цієї технології у середовищі Інтернет речей.
This article introduces a method of hiding transaction amounts in the strongly decentralized anonymous cryptocurrency Monero. Similar to Bitcoin, Monero is a cryptocurrency which is distributed through a proof-of-work “mining” process having no central party or trusted setup. The original Monero protocol was based on CryptoNote, which uses ring signatures and one-time keys to hide the destination and origin of transactions. Recently the technique of using a commitment scheme to hide the amount of a transaction has been discussed and implemented by Bitcoin Core developer Gregory Maxwell. In this article, a new type of ring signature, A Multilayered Linkable Spontaneous Anonymous Group signature is described which allows one to include a Pedersen Commitment in a ring signature. This construction results in a digital currency with hidden amounts, origins and destinations of transactions with reasonable efficiency and verifiable, trustless coin generation. The author would like to note that early drafts of this were publicized in the Monero Community and on the #bitcoin-wizards IRC channel. Blockchain hashed drafts are available showing that this work was started in Summer 2015, and completed in early October 2015. An eprint is also available at http://eprint.iacr.org/2015/1098.
This paper discusses the game theory behind self-contained smart contract provably fair casinos, how they can be gamed by attackers with a large amount of money and computing power, as well as what are the necessary conditions to assure the system cannot be taken advantage of under various configurations.
With the widespread use of Internet, Web, and mobile technologies, a new category of applications and transactions that requires anonymity is gaining increased interest and importance. Examples of such new applications are innovative payment systems, digital notaries, electronic voting, documents sharing, electronic auctions, medical applications, and many others. In addition to anonymity, these applications and transactions also require standard security services: identification, authentication, and authorization of users and protection of their transactions. Providing those services in combination with anonymity is an especially challenging issue, because all security services require explicit user identification and authentication. To solve this issue and enable applications with security and also anonymity we introduce a new type of cryptographically encapsulated objects called BIX certificates. “BIX” is an abbreviation for “Blockchain Information Exchange.” Their purpose is equivalent to X.509 certificates: to support security services for users and transactions, but also enhanced with anonymity. This paper describes the structure and attributes of BIX certificate objects and all related protocols for their creation, distribution, and use. The BIX Certification Infrastructure (BCI) as a distributed public ledger is also briefly described.
Orphan risk for large blocks limits Bitcoin’s transactional capacity while the lack of secure instant transactions restricts its usability. Progress on either front would help spur adoption. This paper considers a technique for using fractional-difficulty blocks (weak blocks) to build subchains bridging adjacent pairs of real blocks. Subchains reduce orphan risk by propagating blocks layer-by-layer over the entire block interval, rather than all at once when the proof-of-work is solved. Each new layer of transactions helps to secure the transactions included in lower layers, even though none of the transactions have been con-firmed in a real block. Miners are incentivized to cooperate building subchains in order to process more transactions per second (thereby claiming more fee revenue) without incur-ring additional orphan risk. The use of subchains also diverts fee revenue towards network hash power rather than dripping it out of the system to pay for orphaned blocks. By nesting subchains, weak block verification times approaching the theoretical limits imposed by speed-of-light constraints would become possible with future technology improvements. As subchains are built on top of the existing Bitcoin protocol, their implementation does not require any changes to Bitcoin’s consensus rules.
This paper is placed in the context of a growing number of social and political critiques of blockchain technologies. We focus on the supposed potential of blockchain technologies to transform political institutions that are central to contemporary human societies, such as money, property rights regimes, and systems of democratic governance. Our aim is to examine the way blockchain technologies canbring about - and justify - new models of governance. To do so, we draw on the philosophical works of Hobbes, Rousseau, and Rawls, analyzing blockchain governance in terms of contrasting social contract theories. We begin by comparing the justifications of blockchain governance offered by members of the blockchain developers’ community with the justifications of governance presented within social contract theories. We then examine the extent to which the model of governance offered by blockchain technologies reflects key governance themes and assumptions located within social contract theories, focusing on the notions of sovereignty, the initial situation, decentralization and distributive justice.