Law, regulation, and private standards have evolved to enhance sustainability in value chains. However, the volume of hard and soft laws has created complexity and fragmentation for consumers and firms. In addition, global value chains are increasingly disaggregated, making it difficult for consumers to enforce breaches of sustainability representations. Blockchain, as an immutable and digital record keeping system, is a tool that can deal with this growing complexity in global value chains. Documents verifying sustainability that were once in the private domain and stored in paper copy can now be made accessible in a secure and transparent blockchain platform. Despite a growing interest in the potential of blockchain to transform businesses, there are few concrete examples or scholarly literature showing how blockchain is operationalized in practice. Using a “conceptual framework analysis” approach, we develop an Evidence, Verifiability, and Enforceability (EVE) framework to illustrate how blockchain can enhance sustainability by providing information to consumers on the origin of products, assurances as to the veracity of the information, and a mechanism to enforce representations through the blockchain smart contract function. However, there need to be safeguards put in place for blockchain technology to meet its promise and we discuss some of these challenges.
In summary, this study has applied TAM model to examine cryptocurrency payment adoption in Taiwanese hotels, examining the factors that are more likely to affect the behavioral intent. The empirical results suggest that intent to adopt cryptocurrency payments is affected by perceived usefulness, and perceived ease of use of these payments. In turn, perceived usefulness is affected by trust towards these payments. Interestingly, perceived usefulness was not shown to be significantly affected by different types of risks associated with cryptocurrency payments, including financial risk, technological risk, and social risk. Perceived ease of use, in turn, is affected by convenience of cryptocurrency payments; and is not shown to be significantly affected by trust.
Since the inception of blockchain and Bitcoin (Nakamoto (2008)), a decentralized-distributed ledger system and its associated cryptocurrency, respectively, the world has witnessed a slew of newer adaptations and applications. Although the original distributed ledger technology (DLT) of blockchain is deemed secure and decentralized, the confirmation of transactions is inefficient by design. Recently adopted, directed acyclic graph (DAG)-based distributed ledgers validate transactions efficiently without the physically and environmentally costly building process of blocks (Lerner (2015)). However, centrally-controlled confirmation against the odds of multiple validation disqualifies the DAG as a decentralized-distributed ledger. In this regard, we introduce an innovative DLT by reconstructing a chain of antichains based on a given DAG-pool of transactions. Each antichain (box) contains distinct nodes whose approved transactions are recursively validated by subsequently augmenting nodes. The boxer node closes the box and keeps the hash of all transactions confirmed by the box-genesis node. Designation of boxers and box-geneses is conditionally randomized for decentralization. The boxes are serially concatenated with recursive confirmation (boxchain) without incurring the cost of box generation. Rewards (boxcoin) are paid to the contributing nodes of the ecosystem whose trust is built on the doubly-secure protocol of confirmation. A value-preserving medium of payment (boxdollar) is among numerous practical applications discussed herein.
Civic crowdfunding (CC) is a popular medium for raising funds for civic projects from interested agents. With Blockchains gaining traction, we can implement CC in a reliable, transparent, and secure manner with smart contracts (SCs). The fundamental challenge in CC is free-riding. PPR, the proposal by Zubrickas [23] of giving refund bonus to the contributors, in the case of the project not getting provisioned, has attractive properties. However, as observed by Chandra et al. [7], PPR faces a challenge wherein the agents defer their contribution until the deadline. We define this delaying of contributions as a race condition. To address this, their proposal, PPS, considers the temporal aspects of a contribution. However, PPS is computationally complex, expensive to implement as an SC, and it being sophisticated, it is difficult to explain to a layperson. In this work, our goal is to identify all essential properties a refund bonus scheme must satisfy in order to curb free-riding while avoiding the race condition. We prove Contribution Monotonicity and Time Monotonicity are sufficient conditions for this. We propose three elegant refund bonus schemes satisfying these two conditions leading to three novel mechanisms for CC - PPRG, PPRE, and PPRP. We show that PPRG is the most cost-effective mechanism when deployed as an SC. We show that under certain modest assumptions on valuations of the agents, in PPRG, the project is funded at equilibrium.
Blockchain has the potential to revolutionize the way we store, use, and process data. Information on most blockchains can be viewed by every node hosting the blockchain, which means that most blockchains cannot handle private data. Decentralized databases exist that guarantee privacy by encrypting user data with the user's private key, but this prevents easy data sharing. However, in many real world applications, from student data to medical records, it is desirable that user data is anonymously searchable. In this paper we present a novel system that gives users ownership over their data while at the same time enabling them to make their data searchable within previously agreed upon limits. Our system implements a strong notion of ownership using a self-sovereign identity system and a weak notion of ownership using multiple centralized databases together with a blockchain and a tumbling process. We discuss applications of our methods to university's student records and medical data.
We investigate a family of bugs in blockchain-based smart contracts, which we call event-ordering (or EO) bugs. These bugs are intimately related to the dynamic ordering of contract events, i.e., calls of its functions on the blockchain, and enable potential exploits of millions of USD worth of Ether. Known examples of such bugs and prior techniques to detect them have been restricted to a small number of event orderings, typicall 1 or 2. Our work provides a new formulation of this general class of EO bugs as finding concurrency properties arising in long permutations of such events. The technical challenge in detecting our formulation of EO bugs is the inherent combinatorial blowup in path and state space analysis, even for simple contracts. We propose the first use of partial-order reduction techniques, using happen-before relations extracted automatically for contracts, along with several other optimizations built on a dynamic symbolic execution technique. We build an automatic tool called ETHRACER that requires no hints from users and runs directly on Ethereum bytecode. It flags 7-11% of over ten thousand contracts analyzed in roughly 18.5 minutes per contract, providing compact event traces that human analysts can run as witnesses. These witnesses are so compact that confirmations require only a few minutes of human effort. Half of the flagged contracts have subtle EO bugs, including in ERC-20 contracts that carry hundreds of millions of dollars worth of Ether. Thus, ETHRACER is effective at detecting a subtle yet dangerous class of bugs which existing tools miss.
For decentralised P2P networks, it is very important to have a mechanism in place that allows the nodes to control resource usage and prevent flooding and denial-of-service attacks with spam. In this paper, we discuss and compare the different approaches to fully decentralised resource control that are used by projects in the cryptocurrency space. The introduced methods are then applied to design a decentralised exchange for Namecoin names (or more generally, crypto assets) as an example.
Internet of Things (IoT) is becoming necessities of people's daily life and establishing itself as an essential part of future Internet. One of the challenges for using IoT is the security of data collected by trillions of IoT devices and used by millions of services. Distributed ledger technology (DLT) provides a distributed security method which can benefit IoT. Yet challenges are put forward when integrating DLT with IoT, such as scalability and heterogeneous capability of IoT devices. In this paper, we propose a mechanism for integrating DLT in IoT by using edge computing technology, taking the scalability and heterogeneous capability of IoT devices into consideration. IoT devices are clustered dynamically into groups based on various proximity context information.
Implementation of Law Number 28 Year 2009 About Local Taxes and Levies and Qanun of Nagan Raya Regency Number 13 Year 2011 About Land Tax Rural and urban sector buildings have regulated the tax system of rural and urban land building taxes that were originally a central tax now become tax region, this is a form of follow-up of regional autonomy and existing fiscal decentralization. The result of the tax management 100% (one hundred percent) goes to the local treasury so that there is no more tax revenue sharing to the central government. One of the supporting aspects of success is through community participation. This study aims to determine how the role of government in every process of making policy, strategy, communication dispute resolution and role as therapy in society. This research uses qualitative descriptive method, based on the data obtained from the results of this study is described with the sentence according to the category to conclude, the data in the form of observation, interview and documentation.The results of this study indicate that the role of local government to increase the participation of the people paying the rural and urban land tax building is done through efforts such as improving the tax and retribution services through the simplification of administrative systems and procedures, raising public awareness through socialization approach, impose a 2% penalty per month for taxpayers who are late in paying taxes on PBB-P2, improving the quality of employees or tax collectors, improving and structuring the procedures of the financial administration system to prevent errors, leaks or deviations from the use of funds thereby through efforts made by the Regional Government Nagan Raya District is running well. This can be proven through data obtained by researchers through the Regional Finance Management Agency of Nagan Raya District, the increase of the number of taxpayers and the UN-P2 revenue from 2014-2016 in Nagan Raya District.Keywords : The role, local government, public participation, tax land sector buildingrural and urban areas
A significant progress in modern power grids is witnessed by the tendency of becoming complex cyber‐physical systems. As a fundamental physical infrastructure, smart meter in the demand side provides real‐time energy consumption information to the utility. However, ensuring information security and privacy in the meter data aggregation process is a non‐trivial task. This study proposes a distributed, privacy‐preserving, and secure meter data aggregation framework, backed up by Blockchain and homomorphic encryption (HE) technologies. Meter data are aggregated and verified by a hierarchical Blockchain system, in which the consensus mechanism is supported by the practical Byzantine fault tolerance algorithm. On the top of the Blockchain system, HE technology is used to protect the privacy of individual meter data items during the aggregation process. Performance analysis is conducted to validate the proposed method.
In the irrigated agricultural areas of Pakistan, the major sources of irrigation are canal water and groundwater. Due to the scarcity of canal water the dependency on groundwater is rapidly increasing in many areas of Pakistan. The groundwater is not only expensive, inadequate, and non-affordable for the small farmers but also of inferior quality. Much of the wastewater which is produced in urban and peri-urban areas is directly or indirectly used for irrigation without any kind of treatment. It appears that suitable technologies for decentralized treatment are avoided but other barriers to the wide adoption of the decentralized approach also exists. These barriers include lack of finance and suitable land, devoid of knowledge and skills and a lack of flexibility in official design standards. This study is an effort to check the status of treatment of the wastewater generated in Faisalabad: The area irrigated with wastewater in and around Faisalabad, quality of wastewater used to grow crops in wastewater irrigated areas, types of crops grown with wastewater, mechanism and composition of wastewater used and supplied to the farmers and farmer’s perception about the social and adverse impacts on human health and constraints in wastewater irrigation. To reduce these barriers several opportunities for improving wastewater management are to be considered via improved policies, institutional dialogues and financial mechanisms, which would reduce the risks in food chain contamination in agriculture practices. Effluent standards combined with incentives or enforcement can motivate improvements in water management by household and industrial sectors discharging wastewater from point sources. Segregation of chemical pollutants from urban wastewater facilitates treatment and reduces risk. Strengthening institutional capacity and establishing links between water delivery and sanitation sectors through inter-institutional coordination leads to more efficient management of wastewater and risk reduction. Key words: Wastewater irrigation, wastewater implication, constraints, farmer ‘perception, food chain contamination.
Currently, the number of Internet of Thing (IoT) devices making up the IoT is more than 11 billion and this number has been continuously increasing. The prevalence of these devices leads to an emerging IoT business model called Device-as-a-service(DaaS), which enables sensor devices to collect data disseminated to all interested devices. The devices sharing data with other devices could receive some financial reward such as Bitcoin. However, side-channel attacks, which aim to exploit some information leaked from the IoT devices during data trade execution, are possible since most of the IoT devices are vulnerable to be hacked or compromised. Thus, it is challenging to securely realize data trading in IoT environment due to the information leakage such as leaking the private key for signing a Bitcoin transaction in Bitcoin system. In this paper, we propose LRCoin, a kind of leakage-resilient cryptocurrency based on bitcoin in which the signature algorithm used for authenticating bitcoin transactions is leakage-resilient. LRCoin is suitable for the scenarios where information leakage is inevitable such as IoT applications. Our core contribution is proposing an efficient bilinear-based continual-leakage-resilient ECDSA signature. We prove the proposed signature algorithm is unforgeable against adaptively chosen messages attack in the generic bilinear group model under the continual leakage setting. Both the theoretical analysis and the implementation demonstrate the practicability of the proposed scheme.
Open access
3 source records
Blockchain Technology Applications and Security
Cryptography and Data Security
Advanced Steganography and Watermarking Techniques
Blockchain technology is swiftly entering the fields of humanitarian and development aid. While it has the potential to revolutionize the aid sector, e.g., through pairing smart contracts with forecast-based financing, it also has the potential to perpetuate societal problems and add new risks. This essay outlines the use cases of Blockchain technology for the humanitarian and development sectors and reflects on potentials and pitfalls that come with the adaptation of this new technology.
Blockchain is a data structure of data blocks arranged in chronological order. It is featured by decentralization, trustworthiness, data sharing, security, etc. It has been widely used in digital currency, smart contract, credit encryption and other fields. With the development of the Internet technology, online education, a novel education mode, has been greatly popularized. However, this education mode still faces many problems in course credibility, credit and certificate certification, stu-dent privacy, and course sharing. Through literature review and case analysis, this paper discusses the basic technical principles and application features of blockchain technology, and proposes a solution to the problems of online educa-tion based on blockchain technology. The blockchain technology can store learn-ing records in a trusted, distributed manner, provide credible digital certificates, realize learning resource sharing with smart contract, and protect intellectual property through data encryption. The research shows that the integration of blockchain technology is a promising trend in the development of online educa-tion.
Blockchain and distributed ledger technology (DLT) research encompasses use cases ranging from social innovation to banking, and technical developments ranging from cryptography to semantics of legal text. Research in both academia and industry is highly interdisciplinary across domains such as computer science, linguistics, law, cryptography, banking, economics, and social sciences. The growing complexity of blockchain science and use cases, coupled with the interdisciplinary nature of the research, poses new challenges to our community. Research publication plays a key role in supporting this highly interdisciplinary work: supporting the need for rapid and reliable dissemination of preliminary and final results, and the need for longevity of results beyond the end of financial or management support for a research project. Industry teams rarely have subscriptions to academic journals, and an open access journal adds substantial value in supporting the research community. The field is young, with many research challenges to be addressed. One “grand challenge” for our research community is the implementation of high-value, long-lived, financial derivatives transactions running as smart contracts on DLT (“smart financial derivatives”). This is currently being explored by academia, banking practitioners, trade associations and technology vendors, and is driving research across a wide range of research groups, each focusing on a different aspect. What makes this a “grand” challenge is the need for a large number of diverse research problems to be solved simultaneously. The following outlines a few of the major research questions being investigated: some of these are general research problems that affect blockchain/DLT development broadly, whereas others are very specific to financial derivatives, but all of these aspects must be solved, and their solutions combined effectively, to provide efficient and resilient solutions to the grand challenge.
Daejun Park, Yi Zhang, Manasvi Saxena, Philip Daian · 5 authors
In this paper, we present a formal verification tool for the Ethereum Virtual Machine (EVM) bytecode. To precisely reason about all possible behaviors of the EVM bytecode, we adopted KEVM, a complete formal semantics of the EVM, and instantiated the K-framework's reachability logic theorem prover to generate a correct-by-construction deductive verifier for the EVM. We further optimized the verifier by introducing EVM-specific abstractions and lemmas to improve its scalability. Our EVM verifier has been used to verify various high-profile smart contracts including the ERC20 token, Ethereum Casper, and DappHub MakerDAO contracts.
Nelson Kibichii Bore, Ravi Kiran Raman, Isaac M. Markus, Sekou L. Remy · 11 authors
Policy decisions are increasingly dependent on the outcomes of simulations and/or machine learning models. The ability to share and interact with these outcomes is relevant across multiple fields and is especially critical in the disease modeling community where models are often only accessible and workable to the researchers that generate them. This work presents a blockchain-enabled system that establishes a decentralized trust between parties involved in a modeling process. Utilizing the OpenMalaria framework, we demonstrate the ability to store, share and maintain auditable logs and records of each step in the simulation process, showing how to validate results generated by computing workers. We also show how the system monitors worker outputs to rank and identify faulty workers via comparison to nearest neighbors or historical reward spaces as a means of ensuring model quality.
Antônio Unias de Lucena, Marco Aurélio Amaral Henriques
Um computador quântico com alta capacidade de processamento quebrará as assinaturas digitais utilizadas nos principais blockchains. Este trabalho traz um estudo preliminar sobre a adoção de assinaturas baseadas em hash no blockchain do Bitcoin para torná-lo resistente ao computador quântico. O estudo mostra os pontos a serem modificados e seus impactos. O maior deles refere-se ao tamanho da assinatura digital, que influencia no tamanho de uma transação e diminui o número de transações por bloco. Soluções para este problema incluem o aumento do tamanho do bloco, a diminuição do tamanho das assinaturas baseadas em hash e/ou a adoção de algoritmos pós-quânticos que produzam assinaturas digitais menores.
Davi R. Ortega, Catherine M. Oikonomou, H. Ding, Prudence Rees-Lee · 6 authors
Abstract Three-dimensional electron microscopy techniques like electron tomography provide valuable insights into cellular structures, and present significant challenges for data storage and dissemination. Here we explored a novel method to publicly release more than 11,000 such datasets, more than 30 TB in total, collected by our group. Our method, based on a peer-to-peer file sharing network built around a blockchain ledger, offers a distributed solution to data storage. In addition, we offer a user-friendly browser-based interface, https://etdb.caltech.edu , for anyone interested to explore and download our data. We discuss the relative advantages and disadvantages of this system and provide tools for other groups to mine our data and/or use the same approach to share their own imaging datasets.
Open access
2 source records
Innovative Microfluidic and Catalytic Techniques Innovation
Emilija Stojmenova Duh, Andrej Duh, Uroš Droftina, Tim Kos · 7 authors
Scholarly communication is today immersed in publish or perish culture that propels noncooperative behaviour in the sense of strategic games played by researchers. Here we introduce and describe a blockchain based platform for decentralized scholarly communication. The design of the platform rests on community driven publishing reviewing processes and implements incentives that promote cooperative user behaviour. Key to achieve cooperation in blockchain based scholarly communication is to transform a static research paper into a modifiable research paper under continuous peer review process. We describe and discuss the implementation of a modifiable research paper as a smart contract on the blockchain.
Nguyen Cong Luong, Tran The Anh, Huỳnh Thị Thanh Bình, Dusit Niyato · 6 authors
To ensure that the data aggregation, data storage, and data processing are all performed in a decentralized but trusted manner, we propose to use the blockchain with the mining pool to support IoT services based on cognitive radio networks. As such, the secondary user can send its sensing data, i.e., transactions, to the mining pools. After being verified by miners, the transactions are added to the blocks. However, under the dynamics of the primary channel and the uncertainty of the mempool state of the mining pool, it is challenging for the secondary user to determine an optimal transaction transmission policy. In this paper, we propose to use the deep reinforcement learning algorithm to derive an optimal transaction transmission policy for the secondary user. Specifically, we adopt a Double Deep-Q Network (DDQN) that allows the secondary user to learn the optimal policy. The simulation results clearly show that the proposed deep reinforcement learning algorithm outperforms the conventional Q-learning scheme in terms of reward and learning speed.
ABSTRACT This study aimed to determine the ability of local revenue (PAD) to the regional finance of Musi Banyuasin Regency. The object of this research is Musi Banyuasin Regency. Data analysis technique used in this research was qualitative analysis technique. The results of this study indicated that the ratio of finance (Decentralization degree) showed that the ability of the original income of the district government of Musi Banyuasin could be said to be not good / independent. It was because the average comparison between Local Own Revenue (PAD) to the Total Revenue District Government of Musi Banyuasin less than 50%. Effectiveness ratio showed that on average from 2010 to 2014 amounted to 103.23%. This could be said to be effective because with the target set was worth more than 100%. With the realization of local revenues on average by 103.23%, the Local Own Revenue (PAD) of Musi Banyuasin Regency based on the ratio of the effectiveness of local revenue was good enough. The degree of Fiscal Autonomy (DOF) of 4.31% with very less criteria. This means that the tendency of the ability of local government of Musi Banyuasin Regency in self-financing activities of government administration, development and service to the community was still very low. Routine Capability Indicators (IKR) of Musi Banyuasin Regency from 2012 to 2014 were up down, on average Index Routine Capability (IKR) was 4.23% with very less criteria. This indicated that the Government of Musi Banyuasin Regency was dependent on the central government
Stakeholder participation is a cornerstone of effective Requirements Engineering (RE). It supports the development and evolution of software systems so that they fit their intended purpose within their application domain. To enable successful stakeholder participation RE experts have created a broad variety of approaches for different circumstances and project phases. These approaches focus on traditionally dedicated software systems, which have closed and location-bound user groups. The stakeholders of these systems usually are members of the organizations that commission or build the system. Meanwhile, technological development has opened doors for ubiquitously deployed and openly available software systems. Stakeholders of these systems are rarely members of those organizations. Instead, they are so-called outside organizational reach and typically unknown to RE experts. Hence, in contrast to stakeholders of traditionally dedicated software systems, they can neither straightforwardly be identified nor be requested to participate in RE. Moreover, they are likely location-independent, numerous and highly heterogeneous. Current RE approaches do not suffice to address these challenges. Established RE approaches provide limited means to identify stake- holders outside organizational reach, let alone motivate them to voluntarily participate in RE. They also cannot support collaboration in distributed settings or on a large scale, yet, collaboration is known to be essential for the development of novel systems and in unknown domains. Feedback mechanisms and social network sites enable distributed and large-scale collaboration. However, their effectiveness is limited as they originally have no RE purpose and typically are restricted to their members. Latest RE approaches close this gap and also apply motivation strategies, which, however, are simplified, missing the high heterogeneity of stakeholders out- side organizational reach; thus, risking to demotivate them. This thesis presents the GARUSO (Game-based Requirements Elicitation) approach, a novel RE approach specifically designed for stakeholders outside organizational reach. It provides (1) a strategy to identify them and (2) a social media based platform that enables their collaborative participation in RE and applies gamification to motivate them to do so. The GARUSO platform is the core of the thesis. Its conceptual solution is inspired by the structure of user stories, the experiential learning theory, motivational psychology and game design. As a proof of concept, it was implemented to elicit and prioritize requirements and evaluated in a field study with promising results: The identified stakeholders build a highly heterogeneous crowd which participated - over a period of three months - in platform activities. They perceived the platform easy to understand, interesting to use and during their participation increased their knowledge on the application domain of the software system of interest.
Lennart Ante, Philipp Sandner, Ingo Fiedler, Andranik Tumasjan · 5 authors
This study explores the determinants of initial coin offering (ICO) success, where success is defined as the amount of capital a project could raise. ICOs are a tool for startups in the blockchain ecosystem to raise early capital with relative ease. The market for ICOs has grown at a rapid pace since its start in 2013. We analyze a unique dataset of 278 projects that finished their ICOs by August 2017 to assess determinants of funding success that we derive from the crowdfunding and venture capital literature. Our results show that ICOs exhibit similarities to classical crowdfunding and venture capital markets. Specifically, we identify resemblances in determinants of funding success regarding human capital characteristics, business model quality, project elaboration, and social media activity.