Blockchain Papers

Hiryu Kawaguchi, Yasunao Takano, Hiroshi Sakuta

No abstract is available for this record.

Stefano Bistarelli, Gianmarco Mazzante, Matteo Micheletti, Leonardo Mostarda · 5 authors

No abstract is available for this record.

Shivansh Pandey, Shivam Goel, Subodh Bansla, Dhiraj Pandey

Online crowdfunding enables people to raise funds for their project. People who are interested in a project can donate by making an online transaction. The donated money goes to the project manager, which he uses to complete the project or to make a product. This existing method of online crowdfunding has a major drawback. It does not allow contributors to have control over the money they have contributed. Since in the existing method the project manager has all the control over the money contributed he can very easily perform malicious activities. Here we address this problem faced by the existing online crowdfunding platforms by using ethereum network and smart contract. The development of Blockchain technology has allowed businesses to build decentralized models. It has derived new methods to conduct transactions and make agreements. One of the technologies that propose an alternative to the traditional model is the smart contract. A smart contract is similar to a contract in the physical world, but it is digital and represented by a tiny computer program stored in a blockchain. These smart contracts can be used to implement logic. A method has been proposed here that uses smart contract to manage all the activities performed in a crowdfunding campaign. The proposed method has been implemented and its various features are tested by funding campaigns on rinkeby test network.

Sudarshan Chavan, Pankaj Warke, Suraj Ghuge, Rugved Deolekar

Modern day entertainment and music streaming has largely been dependent on digital technologies. People prefer subscription based online services to buying physical copies of the music albums. Online streaming services like Spotify, Apple iTunes, Google Music offer great services to the listener with ease. However, drawbacks to these systems includes long delays in payouts for the artists, lack of transparency, confusing payments and licensing terms. In this paper we propose an application that solves all these three drawbacks by making use of Ethereum blockchain and IPFS protocol. The Ethereum blockchain is used for recording transactions and payment management using smart contracts. As storing large files on the Ethereum network costs a lot, the IPFS protocol is used for storing music files, which is a peer to peer protocol. The frontend is built using Web3.js and both listener and artist interact on the blockchain through browser. A PPP(Pay-Per-Play) model with fixed price or as per artist will be defined in the smart contract. The artist can also add other benefactors and share the pay with them. Streaming will be a free service; however, the listeners can tip the artists for supporting. PPP is a smart contract that will be running on the Ethereum blockchain that will be used to set and reward artists with a fixed set of tokens, native currency of platform, per play. Miners will mine new blocks to be added to the blockchain, for which they will be incentivized with tokens. 25 percent of tokens mined per block will go towards a pool for paying artists for streams of their music. The IPFS nodes for storing and distribution of music will be controlled by the artists. Thus, a complete autonomous system for music streaming can be built with least involvement of third parties, and a direct relationship between artist and listener.

Michel Zadé, Jonas Myklebost, Peter Tzscheutschler, Ulrich Wagner

\begin{abstract} When an author under the pseudonym Satoshi Nakamoto published the paper `Bitcoin: A Peer-to-Peer Electronic Cash System' in 2008, the first cryptocurrency using the new blockchain technology was introduced. Over the last decade, more than 1000 different cryptocurrencies, such as Ethereum, Ripple, and Litecoin were developed and Bitcoin's currency had almost reached an equivalent value of \SI{20000}{\$\per BTC}. After recognizing the disrupting momentum that the blockchain technology generated, scientists started to develop blockchain use cases for the energy sector. However, the scientific literature so far offers only rough and incomplete estimations when questions about the current and future energy consumption of the Bitcoin network are raised. This paper introduces a new scenario model to estimate the mining power demand of the Bitcoin and Ethereum network. Six scenarios are developed on the basis of mining hardware efficiency and network parameter data. The results show that an increase of the mining hardware efficiency will only have a limited impact on the overall power demand of blockchain networks. Furthermore, the current power demand of the Ethereum network is in the range from \SIrange{0.6}{3}{\giga\watt} and therefore, is similar to the one of Bitcoin. In case of linear growth of the block difficulty and sigmoidal increase of the hardware efficiency until the year of 2025, the mining power demand for the Bitcoin blockchain will be approximately \SI{3}{\giga\watt}. Furthermore, the model and the scenarios are adaptable to other cryptocurrencies that use the proof-of-work consensus algorithm to create scenarios for their future power demand.

Muhannad Abdul Moneim Uday, P. Devi Prasad, N. Jagadeesh Sai

Energy Trading through Blockchain is an innovative way to trade solar energy across different places. It enables the owners of solar plants to trade the solar energy that is been produced by their plants in an easy and utmost secure manner using Blockchain technology. The core point of the project is to pay for what is being served. The source and destination stations will be abiding to a smart contract which allows them to pay for exactly the served amount of energy. Each and every transaction is stored in a ledger. Operating the entire system in Ethereum platform provides transparency, security and credibility to the process. The process entirely runs on the transfer of cryptocurrencies and not any other mode of money.

Theodosis Mourouzis, Jayant Tandon

The aim of this work is to study the use of decentralization and smart contracts on blockchain networks. We investigate the implementation and use of smart contracts on the platforms Bitcoin, Ethereum and Hyperledger Fabric. Additionally, we have researched consensus algorithms and their respective uses, mentioning both advantages and disadvantages where necessary. To conclude, there is an example contract that is meant to be a close to direct translation of a generic legal house rental contract to show how a legal contract can be translated.

Vitalik Buterin, Daniël Reijsbergen, Stefanos Leonardos, Georgios Piliouras

Summary We present an overview of hybrid Casper the Friendly Finality Gadget (FFG), a proof‐of‐stake checkpointing protocol overlaid onto Ethereum's proof‐of‐work blockchain. We describe its core functionalities and reward scheme and explore its properties. Our findings indicate that Casper's implemented incentives mechanism ensures liveness, while providing safety guarantees that improve over standard proof‐of‐work protocols. On the basis of a minimal impact implementation of the protocol as a smart contract on the blockchain, we discuss additional issues related to parametrization, funding, throughput, and network overhead and detect potential limitations.

Gideon Boako, Aviral Kumar Tiwari, David Roubaud

No abstract is available for this record.

Ricardo Borges dos Santos, Nunzio Marco Torrisi, Erick Reyann Kasai Yamada, Rodrigo Palucci Pantoni

The use of smart contracts and blockchain tokens to implement a consumer trustworthy ingredient certification scheme for commingled foods, i.e., recipe based, food products is described. The proposed framework allows ingredients that carry any desired property (including social or environmental customer perceived value) to be certified by any certification authority, at the moment of harvest or extraction, using the IGR Ethereum token. The mechanism involves the transfer of tokens containing the internet url published at the authority’s web site from the farmer all along the supply chain to the final consumer at each transfer of custody of the ingredient using the Cricital Tracking Event/Key Data Elements (CTE/KDE) philosophy of the Institute of Food Technologists (IFT). This allows the end consumer to easily inspect and be assured of the origin of the ingredient by means of a mobile application. A successful code implementation of the framework was deployed, tested and is running as a beta version on the Ethereum live blockchain as the IGR token. The main contribution of the framework is the possibility to ensure the true origin of any instance or lot of ingredient within a recipe to the customer, without harming the food processor legitimate right to protect its recipes and suppliers.

Peter Robinson, John Brainard

Public blockchains such as Ethereum and Bitcoin provide transparency and accountability, and have strong non-repudiation properties, but fall far short of enterprise privacy requirements for business processes. Consequently consortiums are exploring private blockchains to keep their membership and transactions private. However, private blockchains do not provide adequate protection against potential collusion by consortium members to revert the state of the blockchain. To countenance this, the private blockchain state may be "pinned" to a tamper resistant public blockchain. Existing solutions offering pinning to the public blockchain would reveal the transaction rate of the private blockchain, and do not provide a mechanism to contest the validity of a pin. Moreover, they require that all transactions and members of the private blockchain be revealed. These challenges are hampering the wider adoption of private blockchain technology. We describe the primary author's `Anonymous State Pinning approach', which overcomes these limitations and present a security proof to demonstrate pins can be challenged without compromising these properties. We perform a gas cost analysis of the implementation to estimate the operating cost of this technology, which shows that pinning a private blockchain at the rate of one pin per hour would cost US$508 per year. A hierarchical pinning approach is proposed which would allow many private blockchains to pin to a management blockchain which would then pin to Ethereum MainNet. This approach saves money, but at the cost of increased finality times.

Otto Julio Ahlert Pinno, André Grégio, Luis C. E. Bona

Summary The IoT is changing the way we interact with the world. Very soon, almost all of our daily tasks will be made through self intelligent systems embedded in devices scattered all around us. Their mission is to turn our cities, transportation systems, buildings, homes, and bodies in smart environments. These environments will bring us more comfort, improve our performance, increase our profits, and take away time‐consuming tasks. However, besides its great benefits, the IoT is also a big source of concerns, mainly because a good part of its devices will handle private and confidential information. Recently, cases of successful IoT invasions only worsen this scenario and show us that the today's adopted access control systems need to be replaced by more efficiently and secure ones. To overcome these access control problems, in this work, we present the ControlChain. The ControlChain is an access control authorization architecture that is heavily based on Blockchain technology. We also demonstrate the viability of the ControlChain through the E‐ControlChain, a proof‐of‐concept developed to run over the Ethereum network. Our proposals follows the IoT tendency requirements and are user‐transparent, user‐friendly, fully decentralized, scalable, fault tolerant, and compatible with a wide range of today's access control models already used in the IoT. Finally, we also make a cost and a performance analysis of E‐ControlChain, using a Raspberry Pi as an IoT device.

Riikka Koulu, Kalle Aleksi Markkanen

The blockchain architecture is often envisioned as a potential mechanism for the automation microtransactions between interconnected IoT applications, as transactions could be directly enforced through the technical governance structure it provides. However, this chapter draws attention to the limitations of the blockchain architecture in providing tools for conflict management, which is here considered to be a vital for both governance and the legitimacy of the system. Although blockchain’s potential for conflict prevention is often emphasised, experiences from public blockchain networks such as Ethereum demonstrate that prevention is not sufficient but instead dispute resolution mechanisms are needed for addressing unpredictable events. To this end, alternative conflict management strategies have been developed for blockchain-related disputes. We assess these emergent redress mechanisms from the perspective of conflict management with specific attention to fairness of outcomes and due process rules. By making a distinction between systemic disputes and low intensity disputes we demonstrate how conflict management, governance and technological infrastructure converge on blockchain networks. This convergence, in turn, influences how fairness expectations and due process safeguards are formulated, causing concern for the fairness of emergent conflict management. The design of blockchain-based IoT applications should take into consideration the need for conflict management and particular attention should be paid to the fairness of such mechanisms, as these contribute to the fulfillment of fairness expectations, the legitimacy and predictability of governance structures and, in the end, feasibility of mainstream use.

V. Vijayalakshmi, S. Vimal

The revolution in the system of records has reached a great extent and paves a way for a powerful technology known as blockchain for storing data and performing transactional operations in a decentralized network. Blockchain was first developed to serve as a public transaction ledger for the cryptocurrency named “Bitcoin”. Later, One such application is the online balloting scheme. A ballot is a device that is used to cast the votes in an election. In ballot based voting, still there is no system to avoid proxy casting and recasting. We do not have any technology to view our casted votes. In the electronic voting system based on Blockchain, addresses some of the limitations in the existing systems and labels some of the issues of e-voting. The idea in blockchain enabled balloting scheme is to integrate Aadhaar card and Mobile number of the people using which the OTP is generated and then the voter is allowed to cast their vote. Ethereum is an open source blockchain based technology that uses both private blockchain and remix platform and it acts as a tool in storing the data. The user can cast their votes from anywhere (nearby booth) and the corresponding contestant are notified to the users based on their constituency and candidate promises. If NOTA votes crossed above 50%, then all the candidates are disqualified and are permitted to contest for the next election. If any of the citizen do not poll their vote, then a warning message will be sent to the respective person. They should provide a valid reason for not voting within a period of 6 months, if the reason is invalid then necessary action will be taken by the government. If a member of citizen wants to view his/her voting status then they can view it by entering their aadhar number and the block number that is sent to them through the mobile app. The implementation of this system addresses most of the issues faced in the balloting scheme and is used to avoid proxy casting and recasting and is also used to achieve above 95% of the vote.

Olga Naumova, I. A. Svetkina, D.V. Naumov

The article identifies the main features of the application of blockchain technology, which caused a lot of positive feedback in scientific circles and professional communities. After success in the financial market, where the blockchain contains blocks that are iced in the chain, which describes absolutely all transactions with virtual coins (such as Bitcoin, Litecoin, Ethereum and others), there were prospects for evaluating the possibility of its successful application in other areas. Considering that the sphere of education in Russia is going through a period of reforms, special attention is paid to the opportunities and problems of application in this sphere. The article discusses the effectiveness of the application of blockchain technology for the distributed registry and for mass application in the field of education. And also an estimation of the probability of the possibility of improving the educational process. The analysis of the advantages of the technology that allowed it to successfully spread its crypto currency in the market of anonymous transactions and their application in the subject field of education, in comparison with classical technologies, with the central node-regulator, for example, the client-server.

Florian Wessling, Christopher Ehmke, Ole Meyer, Volker Gruhn

Blockchain-based applications usually consist of centralized elements (e.g., web servers and back-end logic) connected to decentralized elements such as smart contracts. The engineering of such hybrid software architectures poses a challenge as it is unclear which elements should be centralized or decentralized. Furthermore the impact of this decision (or the balance between those two areas) on software quality attributes such as security, maintainability, performance or costs is currently unknown. The goal is to build a software architecture using the benefits and handling the challenges of blockchain technology while fulfilling the relevant quality attributes. While there are several approaches examining the relation between architectural decisions and quality attributes in centralized systems, research is at an early stage for decentralized elements in software architectures. This paper presents a first step towards architectural blockchain tactics. With a simplified experiment comparing two implementation variants of an Ethereum smart contract we show that software design patterns are not always beneficial and that the expected usage scenarios have a strong impact on the operational costs. We argue that further research and validation is necessary for gaining more qualitative and quantitative insights to make informed architectural design decisions when using blockchain technology and give a first outline on how to achieve this.

Runchao Han, Nikos Foutris, Christos Kotselidis

Blockchain technology has become extremely popular, during the last decade, mainly due to the successful application in the cryptocurrency domain. Following the explosion of Bitcoin and other cryptocurrencies, blockchain solutions are being deployed in almost every aspect of transactional operations as a means to safely exchange digital assets between non-trusted parties. At the heart of every blockchain deployment is the consensus protocol, which maintains the consistency of the blockchain upon satisfying incoming transactions. Although many consensus protocols have been recently introduced, the most prevalent is Proof-of- Work, which scales the blockchain globally by converting the consensus problem to a competition based on cryptographic hash functions; a process called “mining”. The Proof-of- Work consensus protocol employs memory-hard algorithms in order to counteract ASIC or FPGA mining that may compromise the decentralization and democratization of the blockchain. Unfortunately, this leads to increased power consumption and scalability challenges since numerous processing units such as GPUs, FPGAs, and ASICs, are required to satisfy the ever-increasing operational requirements of blockchain deployments. In this paper, we perform an in-depth performance analysis and characterization of the most common memory-hard PoW algorithms running on NVIDIA GPUs. Motivated by our experimental findings, we apply a series of optimizations on Ethash algorithm, the consensus protocol of the Ethereum blockchain. The implemented optimizations accelerate performance by 14% and improve energy efficiency by 10% when executing on three NVIDIA GPUs. As a result, the optimized Ethash algorithm outperformed its fastest commercial implementation.

Gerard Rovira Sánchez

As a decentralized blockchain network, Ethereum enables us to do immutable, tamper-proof and secure transactions. However, its current design makes it very difficult to trace the real owner behind an address, if not impossible. This thesis aims to give a solution to the verification of identities behind Ethereum addresses, as well as to demonstrate how a third party service can take advantage of it. In particular, we have worked with InVID Rights Management web platform to provide a blockchain-based service to guarantee that the rights given over social media videos are safe, transparent and non-repudiable.

Huayi Duan, Yifeng Zheng, Yuefeng Du, Anxin Zhou · 6 authors

Crowdsensing, driven by the proliferation of sensor-rich mobile devices, has emerged as a promising data sensing and aggregation paradigm. Despite useful, traditional crowdsensing systems typically rely on a centralized third-party platform for data collection and processing, which leads to concerns like single point of failure and lack of operation transparency. Such centralization hinders the wide adoption of crowdsensing by wary participants. We therefore explore an alternative design space of building crowdsensing systems atop the emerging decentralized blockchain technology. While enjoying the benefits brought by the public blockchain, we endeavor to achieve a consolidated set of desirable security properties with a proper choreography of latest techniques and our customized designs. We allow data providers to safely contribute data to the transparent blockchain with the confidentiality guarantee on individual data and differential privacy on the aggregation result. Meanwhile, we ensure the service correctness of data aggregation and sanitization by delicately employing hardware-assisted transparent enclave. Furthermore, we maintain the robustness of our system against faulty data providers that submit invalid data, with a customized zero-knowledge range proof scheme. The experiment results demonstrate the high efficiency of our designs on both mobile client and SGX-enabled server, as well as reasonable on-chain monetary cost of running our task contract on Ethereum.

S. M. Suhail Hussain, Shaik Mullapathi Farooq, Taha Selim Ustun

Proliferation of Distributed Energy Resources (DER) changed power system operation drastically. They introduced generation at distribution level, which was unprecedented. Also, bidirectional power flow created more optimization opportunities such as Demand Side Management (DSM) and Vehicle-to-Grid (V2G) support. These schemes allow for efficient use of grid infrastructure, storage devices and DERs. In order to plan the operation and calculate bills, it is imperative to keep a record of these transactions. When some sort of trading occurs between multiple parties, trust is a major concern. Traditionally, a third part trusted by all keeps the record of transactions. Using blockchain technology for energy trading eliminates the role of trusted third party. This paper discusses the feasibility and benefits of implementing blockchain for smartgrids. It also develops an Ethereum-based implementation of blockchain technology for energy trading. Results are shown for a case where energy transactions are undertaken between Distribution System Operator (DSO) and smart meters of individual houses.

Sufyan Salim Mahmood Aldabbagh, Alyaa Ghanim Suliaman, Khalid Abdulkareem Al-Enezi, Khaled Alhatem

No abstract is available for this record.

Irfan Siddavatam, Ashwini Dalvi, Shivam Pathak, Kshitiz Srivastava

In the domain of Internet of things there are large number of devices generating data in the network and submitting it to their respective configured data collectors. When the sensors are preconfigured by the data collectors, they can easily verify the data coming from those sensors for its authenticity using cryptography. But if a third party wants to buy that data, how can they trust the data collector for the authenticity of that data i.e whether the data they are buying is real data or some randomly generated stream of numbers. In fact, the only option left is to trust the claim made by the collectors that the data they are providing is authentic. This project resolves the trust issue by creating a distributed application using blockchains by distributing the trust factor to the entire network instead of trusting a single entity [5]. This system provides authenticity of data generated by sensor nodes in the network.

Markus Schäffer

Recently, the term blockchain has been on everyones lips due to the media hype which has emerged around the cryptocurrency Bitcoin. Soon the blockchain paradigm has become an inspiration for additional applications next to cryptocurrencies. One type of such applications are smart contracts, i.e. programs which are executed on a blockchain network and move digital assets according to arbitrary pre-specified rules. Utilizing the combination of cryptographically secure mechanisms of a blockchain and the possibility to execute programs on a blockchain network results in promising use cases for the public and the private sector. In order to run smart contracts, a platform such as Ethereum can be used. In contrast to a public smart contract platform, a private version allows to configure some blockchain-specific parameters when setting up the system. Examples of these configuration parameters are the time passing between two consecutive blocks, the size of blocks, the hardware of the nodes running the blockchain software or simply the size of the network. However, how these and other parameters of a private Ethereum smart contract platform affect the performance of the system is still poorly understood. Moreover, it is not clear to which extent these parameters scale and which parameters represent the bottleneck of such systems. In order to tackle this problem, this thesis introduces a novel concept for measuring the performance and scalability of private Ethereum smart contract platforms. This concept is practically implemented in a framework which allows to automatically deploy differently configured private Ethereum smart contract platforms on the cloud for the purpose of gathering performance-related data. Based on the gathered data, various charts were created which visualize the effects on performance when changing a specific parameter. The results of the data analysis conducted show that the effect of variations in one parameter is highly dependent on the configuration of other parameters as well, especially when running the system near its limits. Nevertheless, a structure which depicts the bottlenecks of current private Ethereum smart contract platforms has been identified. Further research may be conducted in order to support additional Ethereum clients and APIs.

Walid Mensi, Mobeen Ur Rehman, Khamis Hamed Al‐Yahyaee, Idries Mohammad Wanas Al-Jarrah · 5 authors

No abstract is available for this record.