Blockchain Papers

Kevin Magnier-Merran

International audience

Ines Ladasic

No abstract is available for this record.

Djamel Eddine Kouicem, Abdelmadjid Bouabdallah, Hicham Lakhlef

No abstract is available for this record.

Francisca Adoma

The importance of big data in machine learning cannot be overemphasized in recent times. Through the evolution of big data, most scientific technologies that relied heavily on enormous data in solving complex issues in human lives gained grounds; machine learning is an instance of these technologies. Various machine learning models that yield groundbreaking throughputs with high efficiency rates in predicting, detecting, classifying, discovering and acquiring in-depth knowledge about events that would otherwise be very difficult to ascertain have been made possible due to big data. Although big data has undoubtedly helped in the field of machine learning research ,over the years, its mode of acquisition has posed great challenge in industries,education and other agencies that obtained them for various purposes. This is because these large quantities of data cannot be stored on personal computers with limited storage capabicity but required the use of high storage capacity servers for effective storage. These servers may be owned by a group of companies or individuals who had the singular priviledge to modify the data in their possession as and when deemed relevant thus the creation of a centralized data storage environment. These were mostly refered to as the Third Parties (TP) in the data acquisition process. For the services they rendered, these trusted parties priced data in their possession expensively. The adverse effect is a limitation on various researches that could help solve a number of problems in human lives. It is worth mentioning that the security of these data being purchased expensively cannot be even assured limiting various researches that thrive on secured data. In order to curb these occurrences and have better machine learning models, the incorporation of Blockchain Technology databases into machine learning. This paper discusses the concept of big data, Machine Learning and Blockchains. It further discusses how Big data has impacted the Machine learning Community, the significance of Machine Learning and how the BlockChain Technology could be used similarly impact the Machine Learning Community. The aim of this paper is to encourge further research in incoporating the BlockChain Technology into Machine Learning.

Michele Marchesi

In the past few years, cryptocurrencies and blockchain applications has been one of the most rapidly emerging fields of computer science, leading to a strong demand of software applications. Several new projects have been emerging almost daily, with an impetus that was not seen since the days of the dawn of the Internet. However, the need of being timely on the market and the lack of experience in a brand new field led to epic disasters, such as those of DAO in 2016 and of Parity Ethereum wallet in 2017. Also, there have been several hacks successfully performed on cryptocurrency exchanges, the biggest being those of MtGox in 2014 (350 million US$), Bitfinex in 2016 (72 million US$), and Coincheck in 2017 (400 million US$). The application of sound SE practices to Blockchain software development, both for Smart Contract and generic Blockchain software, might be crucial to the success of this new field. Here the issues are the need for specific analysis and design methods, quality control through testing and metrics, security assessment and overall development process. At the same time, Blockchain development offers new opportunities, such as the certification of empirical data used for experiment; the ability to design processes where developers are paid upon completion of their tasks through Blockchain tokens, after acceptance tests performed using Smart Contracts; and more sound techniques enabling pay-per-use software, again using tokens.

Stuart Wimbush

No abstract is available for this record.

Georgios Darivianakis, Angelos Georghiou, John Lygeros

Distributed model predictive control (MPC) has been proven a successful method in regulating the operation of large-scale networks of constrained dynamical systems. This paper is concerned with cooperative distributed MPC in which the decision actions of the systems are usually derived by the solution of a system-wide optimization problem. However, formulating and solving such large-scale optimization problems is often a hard task which requires extensive information communication among the individual systems and fails to address privacy concerns in the network. Hence, the main challenge is to design decision policies with a prescribed structure so that the resulting system-wide optimization problem to admit a loosely coupled structure and be amendable to distributed computation algorithms. In this paper, we propose a decentralized problem synthesis scheme which only requires each system to communicate sets which bound its states evolution to neighboring systems. The proposed method alleviates concerns on privacy since this limited communication scheme does not reveal the exact characteristics of the dynamics within each system. In addition, it enables a distributed computation of the solution, making our method highly scalable. We demonstrate in a number of numerical studies, inspired by engineering and finance, the efficacy of the proposed approach which leads to solutions that closely approximate those obtained by the centralized formulation only at a fraction of the computational effort.

Santiago Bragagnolo, Henrique Rocha, Marcus Denker, Sté́phane Ducasse

Solidity is a language used for smart contracts on the Ethereum blockchain. Smart contracts are embedded procedures stored with the data they act upon. Debugging smart contracts is a really difficult task since once deployed, the code cannot be reexecuted and inspecting a simple attribute is not easily possible because data is encoded. In this paper, we address the lack of inspectability of a deployed contract by analyzing contract state using decompilation techniques driven by the contract structure definition. Our solution, SmartInspect, also uses a mirror-based architecture to represent locally object responsible for the interpretation of the contract state. SmartInspect allows contract developers to better visualize and understand the contract stored state without needing to redeploy, nor develop any ad-hoc code.

Maximilian Wöhrer, Uwe Zdun

Smart contracts that build up on blockchain technologies are receiving great attention in new business applications and the scientific community, because they allow untrusted parties to manifest contract terms in program code and thus eliminate the need for a trusted third party. The creation process of writing well performing and secure contracts in Ethereum, which is today's most prominent smart contract platform, is a difficult task. Research on this topic has only recently started in industry and science. Based on an analysis of collected data with Grounded Theory techniques, we have elaborated several common security patterns, which we describe in detail on the basis of Solidity, the dominating programming language for Ethereum. The presented patterns describe solutions to typical security issues and can be applied by Solidity developers to mitigate typical attack scenarios.

Giuseppe Destefanis, Michele Marchesi, Marco Ortu, Roberto Tonelli · 6 authors

Smart Contracts have gained tremendous popularity in the past few years, to the point that billions of US Dollars are currently exchanged every day through such technology. However, since the release of the Frontier network of Ethereum in 2015, there have been many cases in which the execution of Smart Contracts managing Ether coins has led to problems or conflicts. Compared to traditional Software Engineering, a discipline of Smart Contract and Blockchain programming, with standardized best practices that can help solve the mentioned problems and conflicts, is not yet sufficiently developed. Furthermore, Smart Contracts rely on a non-standard software life-cycle, according to which, for instance, delivered applications can hardly be updated or bugs resolved by releasing a new version of the software. In this paper we advocate the need for a discipline of Blockchain Software Engineering, addressing the issues posed by smart contract programming and other applications running on blockchains.We analyse a case of study where a bug discovered in a Smart Contract library, and perhaps "unsafe" programming, allowed an attack on Parity, a wallet application, causing the freezing of about 500K Ethers (about 150M USD, in November 2017). In this study we analyze the source code of Parity and the library, and discuss how recognised best practices could mitigate, if adopted and adapted, such detrimental software misbehavior. We also reflect on the specificity of Smart Contract software development, which makes some of the existing approaches insufficient, and call for the definition of a specific Blockchain Software Engineering.

Zhilei Ren, He Jiang, Jifeng Xuan, Zijiang Yang

Reproducibility is the ability of recreating identical binaries under pre-defined build environments. Due to the need of quality assurance and the benefit of better detecting attacks against build environments, the practice of reproducible builds has gained popularity in many open-source software repositories such as Debian and Bitcoin. However, identifying the unreproducible issues remains a labour intensive and time consuming challenge, because of the lacking of information to guide the search and the diversity of the causes that may lead to the unreproducible binaries. In this paper we propose an automated framework called RepLoc to localize the problematic files for unreproducible builds. RepLoc features a query augmentation component that utilizes the information extracted from the build logs, and a heuristic rule-based filtering component that narrows the search scope. By integrating the two components with a weighted file ranking module, RepLoc is able to automatically produce a ranked list of files that are helpful in locating the problematic files for the unreproducible builds. We have implemented a prototype and conducted extensive experiments over 671 real-world unreproducible Debian packages in four different categories. By considering the topmost ranked file only, RepLoc achieves an accuracy rate of 47.09%. If we expand our examination to the top ten ranked files in the list produced by RepLoc, the accuracy rate becomes 79.28%. Considering that there are hundreds of source code, scripts, Makefiles, etc., in a package, RepLoc significantly reduces the scope of localizing problematic files. Moreover, with the help of RepLoc, we successfully identified and fixed six new unreproducible packages from Debian and Guix.

Robert Crammond, Kingsley Obi Omeihe, Alan Murray, Kirstin Ledger

Purpose The purpose of this paper is to conceptualise social media usage (SMU) as a contributory, knowledge management (KM) tool towards entrepreneurial behaviour amongst small- and medium-sized enterprises (SMEs). Although an underdeveloped concept in entrepreneurship, the conceptual analysis of KM presents evidence which links SMU as complementary to changing KM conventions. Design/methodology/approach The pertinent KM and SMU literatures of the SME context were reviewed to form an understanding of this context. Employing a mixed-methods approach, a pragmatic, thematic investigation of SMU-enhanced KM was facilitated. Findings Substantial benefits of innovative SMU, as a management tool towards SME entrepreneurialism, were witnessed. SMU enhances the administration of real-time knowledge, encouraging creativity. However, longer-term costs of employing requisite personnel, and anticipated organisational restructuring, present challenges. The paper identifies the potentials of social media technologies in overcoming KM issues. The authors propose a reasoned process model towards entrepreneurial exploitation by acknowledging systematic phases of research, concept, institutionalise, develop, target and assess, referred to as the RCIDTA model. Practical implications The authors argue that KM, through social media, facilitates interactions to execute innovative processes within SMEs ever-changing infrastructures. It also informs nascent entrepreneurs, in considering the benefits of systematic KM, and novel SMU, opportunities. The RCIDTA model for SMEs can be utilised in improving knowledge ecosystems of entrepreneurial SMEs, promoting innovation towards sustained organisation growth. Originality/value This paper embraces the growing approach of SMEs applying SMU. SMU and its cost efficiency support the start-up activity. This paper highlights central issues concerning the exploitation of sector-specific KM, including organisational strategy, structure, brand formation, fiscal and personnel resource allocation and market share.

Taneli Hukkinen

This thesis explains the working of a previously undocumented blockchain application developed for the energy sector. The application enables distributed market coordination for small-scale decentralized energy systems. An Ethereum smart contract is employed as a core component of the application, facilitating a marketplace for transacting electrical energy. A design science research methodology was applied to the application in an attempt to further develop it. The problem of high fees in the energy marketplace was identified, resulting from the smart contract's inefficient use of Ethereum gas. Two particular sources of inefficiency were identified, and solutions for fixing these inefficiencies were designed and implemented. Savings in transaction fees were created by replacing a function of the smart contract with off blockchain communication, and by editing the fund withdrawal mechanism of the smart contract so that it requires users to create fewer blockchain transactions. As a result, the smart contract's gas consumption was reduced by up to 11% in a certain use case. The reduction in gas consumption was not sufficient to make the deployment and use of the application economically feasible on the canonical public Ethereum blockchain. A Plasma child chain or a dedicated Ethereum blockchain were suggested as potentially more feasible deployment environments for the application. It was noted that the application relies on centralized components, and it is debatable whether its current blockchain-based implementation is justifiable.

Tom Billitteri

Bitcoin may not last, but blockchain could be the real dealEconomist Nouriel Roubini, aka Dr. Doom since he predicted the 2008 financial crisis, called it "the mother of all bubbles."The head of the Royal Bank of Scotland, Sir Howard Davies, invoked Dante's Inferno to warn investors off it.JPMorgan Chase CEO Jamie Dimon flat-out called

Mirella Pellegrini, Francesco Perna

The evolution of the economic processes is reflected on the way the currency work. The recent development of new methods of payment based on the computer systems – and, in particular, the electronic-based systems used to register the debit\credit position, the operationalization of the market – have elicited the growth of the phenomenon of cryptocurrency, and bitcoin is nowadays the most common. There is still no precise definition of cryptocurrency at the moment, due to the complexity in matching the cryptocurrency with the proper related case in issue. That said, it is crucial as in the face of a growing interest in bitcoins, the predisposition of an adequate control mechanism, still missing, is assuming a more and more importance; and in such a critical context, this lack treats the potential traders in this new segment. The awareness of the effective consistency and diffusion of the phenomenon should encourage the authorities in taking actions against the potential risks, especially for those inexperienced operators that are not able to identify and evaluate them, attracted by the promise of high profits with low investments. One of the most critical aspect in subiecta materia is the fiscal treatment of those bitcoin operations with particular regard to money laundering and terrorism financing. The growing phenomenon of crypto currencies – in addition to introduce potential danger (with evident damages for those who use them improperly) – emphasizes the need to move forward new forms of regulation of such complex matter, so that it can be redefined under the competence of the public authority.

Umar Basni, Sutjipto Ngumar

This research is meant to find out how the preparation of budget and what sort of barriers that are encountered by the Surabaya city government in the preparation of budget. This research is qualitative research approach. The analysisis the local financial performance analysis which is carried out by there venue variance analysis, the degree of the decentralization, the local financial dependency ratios, analysis of variance expenditure, the expenditure efficiency ratio, and financing analysis. In this research, the significant barriers in all existing employment programs at the Revenue Offices of Surabaya city have not been found yet. Based on the result of the calculation and the analysis of the local financial performance, it can be concluded that the difference in budget revenue has negative balance, it indicates that revenue performance is quite well although it cannot earn income which is compatible with the budgeted amount. The regional financial dependency ratio indicates that the Surabaya city government in carrying out its activities does not rely on the central government/province. The analysis of variance shows that difference of expenditure budget has negative balance which indicates that there is an efficiency or budget savings. The financing analysis shows that the SILPA has negative balances the Surabaya city government is appropriate in preparing budget plan or in other words the realization of SILPA does not exceed from what that has already been set in the budget. Keywords : Local government budget, financial performance, effectiveness, efficiency

Jeffrey Quesnelle

No abstract is available for this record.

Daniel Michelson, Anders Henja, Sander Ernes, Günther Haase · 9 authors

BALTRAD software exchanges weather-radar data internationally, operationally, and in real-time, and it processes the data using a common toolbox of algorithms available to every node in the decentralized radar network. This approach enables each node to access and process its own and international data to meet its local needs. The software system is developed collaboratively by the BALTRAD partnership, mostly comprising the national Meteorological and Hydrological institutes in the European Union’s Baltic Sea Region. The most important sub-systems are for data exchange, data management, scheduling and event handling, and data processing. C, Java, and Python languages are used depending on the sub-system, and sub-systems communicate using well-defined interfaces. Software is available from a dedicated Git server. BALTRAD software has been deployed throughout Europe and more recently in Canada. Funding statement: From 2009–2014, the BALTRAD and BALTRAD+ projects were part-financed by the European Union (European Regional Development Fund and European Neighbourhood and Partnership Instrument), with project numbers #009 and #101, respectively.

Sergiy Smetana, Christian Seebold, Volker Heinz

No abstract is available for this record.

Ijazul Haq, Olivier Muselemu

The production and distribution of counterfeit drugs is an urgent and increasingly critical worldwide issue, especially in developing countries. The market value of pharmaceutical counterfeiting has reached billions of dollars annually. One of the reasons for drugs counterfeiting is the imperfect supply chain system in pharmaceutical industry. Drugs change ownership from manufacturers to wholesaler, distributer and then pharmacist before it reach the customer. In current supply chain system, information is not shared between systems, manufacturers don't know what happened to their products, drugs regulatory authority has no visibility of the system, recalls are complicated and costly, and companies cannot follow-up patients. In this paper we explain how to use blockchain technology in pharmaceutical supply chain to add traceability, visibility and security to the drugs supply system. The proposed system will be used in pharmaceutical industry to track the drugs from its manufacturing until its delivery to patient. After the usage of a drug, its effect on patient will be recorded to a database for future statistics. A permissioned blockchain will be used for storing transactions and only trusted parties will be allowed to join the network and push data to blockchain.

M. Niranjanamurthy, B. N. Nithya, S. Jagannatha

Any online transaction that involves digital money is a bit of a challenge these days with the rising threats of hackers trying to steal bank details posted online. This leads to the invention of various kinds of crypto-currency, Bitcoin being one of them. The technology behind using the Bitcoin is popularly called as Blockchain. Blockchain is a digitized, de-centralized, public ledger of all crypto-currency transaction/s. Blockchain tries to create and share all the online transactions, stored in a distributed ledger, as a data structure on a network of computers. It validates the transactions using peer-to-peer network of computers. It allows users to make and verify transactions immediately without a central authority. Blockchain is a transaction database which contains information about all the transactions ever executed in the past and works on Bitcoin protocol. In this analysis paper we discussed what is Blockchain?, SWOT analysis of BC, Types of BC and how Blockchain works along with its advantages and disadvantages.

Satarupa Saha, Jayanta Poray, Bappaditya Jana

Blockchain is a one of emerging technology for decentralized and sharing of transactional data across a large peer to peer network, where non-trusting members can interact with each other without an intermediary, in a verifiable manner. In this paper, we review the basics of Blockchain, its applications, types, and working of Blockchain. Behind this innovative technique, the security, privacy issues and Con-sensus mechanisms of this technology are also important and are a matter of concern. The problems associated with Blockchain technol-ogy are also discussed in this paper.

Eyal Hertzog, Guy Benartzi, Galia Benartzi

The Bancor Protocol enables automatic price determination and an autonomous liquidity mechanism for tokens on smart contract blockchains. These Smart Tokens have one or more connectors to a network that hold balances of other tokens, allowing users to instantly purchase or liquidate a Smart Token for any of its connected tokens directly through the Smart Token’s contract, at a price that is continuously recalculated to balance buy and sell volumes.

Florian Hawlitschek, Benedikt Notheisen, Timm Teubner

No abstract is available for this record.