Cryptocurrency is playing an increasingly important role in reshaping the financial system due to its growing popular appeal and mechant acceptance. While many people are making investments in Cryptocurrency, the dynamical features, uncertainty, the predictability of Cryptocurrency are still mostly unknown, which dramatically risk the investments. It is a matter to try to understand the factors that infiuence the value formation. In this study, we use advanced artificial intelligence frameworks of fully connected Artificial Neural Network (ANN) and Long Short-Term Memory (LSTM) Recurrent Neural Network to analyse the price dynamics of Bitcoin, Etherum, and Ripple. We find that ANN tends to rely more on long-term history while LSTM tends to rely more on short-term dynamics, which indicate the efficiency of LSTM to utilise useful information hidden in historical memory is stronger than ANN. However, given enough historical information ANN can achieve a similar accuracy, compared with LSTM. This study provides a unique demonstration that Cryptocurrency market price is predictable. However, the explanation of the predictability could vary depending on the nature of the involved machine-learning model.
Shibasis Patel, Anisha Sahoo, Bhabendu Kumar Mohanta, Soumyashree S. Panda · 5 authors
Over the past decade, a lot of evolution has happened in the field of security specifically authentication system. The most commonly used authentication service we use now is OAuth 2.0 based authentication. In this method, we are dependent on a 3rd party authentication service provider to which we need to trust. Though this model is used extensively nowadays, studies show that it is still vulnerable to several hacks. In addition to that, the 3rd party authentication provider has total control over the user data to which they can leak or modify at their will. Thus the use of OAuth 2.0 based protocol has raised security and privacy concerns. In this paper, blockchain and its use cases are studied and an alternative way of authentication service has been proposed based on Ethereum Blockchain called DAuth. Furthermore, a prototype has been developed which enables user authentication on the site. DAuth proposes to enhance transparency and user control in transactions which involves identity management.
Due to emerging disruptive technologies, Internet of Things (IoT) play a vital role for smart living domains, for examples, elderly and disabilities healthcare services and home safety and security monitoring and automation control services. These systems will send automatically an emergency call with home user information and location as a privacy data to public services like hospitals, police offices, or fire departments. This paper introduces emergency service for a Smart Home System (SHS) based on Ethereum blockchain with smart contract for decentralized handling access control among untrusted public services so called Home Service Providers (HSPs) and smart home IoT devices. Our SHS testbed consists of (1) smart home sensor manger equipped with Raspberry Pi (RPi) represented as an edge IoT gateway for gathering environmental sensor data, (2) HSP miners deployed Meteor and Ethereum platform, and (3) web-based applications for home users and HSP staffs. Furthermore, our contribution includes the integration of digital signature for the IoT device authentication, the One Time Passcode with QR code for HSP staff access control, and IPFS for manipulating emergency call from SHS in peers. Our implementation results focusing on HSP miners will be presented and analysed.
Linh Vo-Cao- Thuy, Khoi Cao-Minh, Chuong Dang-Le-Bao, Tuan Anh Nguyen
Blockchain, which is the underlying technology of the first cryptocurrency Bitcoin, has drawn a lot of global attention in recent years. Its notable characteristics of the distributed ledger, trustless system, and immutability not only makes it a disruptive innovation in the electronic payment industry but also potential solutions for other areas that require trust establishment. Electronic voting (E-voting) scheme is a use-case where all attributes of blockchain can offer a mechanism for an open, fair and universally verifiable electoral process. In this paper, we review the requirements and then propose Votereum, an E-voting system that utilizes the blockchain technology. The proposed system is empowered by Ethereum platform, including one server manages the entire system and the other handles all blockchain-related requests. The implementation is also deployed to Rinkeby testing network for evaluation on the feasibility and discussion on some security concerns, which are mentioned in the conclusion of this paper.
Internet Traffic Analysis and Secure E-voting
Cryptography and Data Security
Advanced Steganography and Watermarking Techniques
R. Aroul Canessane, N. Srinivasan, Abinash Beuria, Ashwini Kumar Singh · 5 authors
The concept of blockchain without a doubt is a revolutionary concept. It is the underlying Technology behind bitcoin and many more cryptocurrencies. Although the people's focus being only at blockchain as cryptocurrencies in everyday services to do payments online without the interference of a third party will try to replace the current method of cash which is a really slow and ancient method. Blockchain is a zero trust network and this makes it a very powerful tool for various services provided that people are ready to believe and invest in it. In the Ethereum world, the blockchain runs on smart contracts which are self-executing applications that come at a cost of security. This zero-trust network is capable of replacing many of the debated process or activities in our day to day life. One of our biggest concerns is an E-voting system which must be secure. Blockchain being an immutable and append only ledger will not allow for any tampering while also being fully transparent. In this paper, we have implemented and tested a sample e-voting app running as a smart contract for ethereum network using E-Wallets. After an election is held, eventually, the ethereum blockchain will hold the records of ballots and voters thus giving us a clear and trusty network where mishandling is to a minimum.
The article presents the results of a study of the theoretical foundations of the Blockchain technology. The analysis of the organization structure of its units and the principles of the system. Algorithms of smart contracts are considered and their advantages and disadvantages are analyzed. The purpose of the study is that based on the analysis of the theoretical foundations of building systems using blockchain technology and introducing them into various areas, to propose a system model using smart contracts on the Etherium platform for use in the workflow system in institutions of higher education. Convenient web interfaces for managing the creation of a contract and a module for the interaction of smart contracts with a Web application have been developed. The management of an institution of higher education, namely, a department, faculty or institute, involves the correct and timely preparation of various documentation, in which the documentation on student learning outcomes holds a special place. On its basis various financial and reporting documents are being prepared. To this end, institutions of higher education are introducing workflow system and office automation systems to manage the processing of documents, as well as to organize control over the implementation of these processes. The paper proposes the introduction of a blockchain system on the Ethereum platform using smart contracts written in the Solidity language. Solidity is a tool that is used to create machine-level code that can be run on an Ethereum Virtual Machine. Solidity allows you to create and execute a smart contract without requiring centralized or trusted parties. The use of such technologies makes it possible to significantly reduce the number of paper-based information carriers and, to a significant extent, further automate the existing the workflow system in institutions of higher education. The proposed system is a part of the workflow system of institutions of higher education, which is designed to automate the process of passing documents related to taking into account and submitting to the dean's office of the faculty or the institute the results of the final controls on academic disciplines or the results of retake of tests and exams. This process requires a large number of documents on paper. The proposed system is deployed in the local computer network of the Educational and Scientific Institute of Information Technologies and Mechatronics of Poltava National Technical Yuri Kondratyuk University and is being tested. The results allow us to draw conclusions about the reduction in the number of paper documents; time to obtain permits. In addition, the level of reliability and protection of information transmitted to the administration of the faculty or institute for further processing has increased. In the future, it is planned to introduce the proposed system for document flow automation for all institutes and faculties of the Poltava National Technical Yuri Kondratyuk University.
ABSTRACT The Ethereum block chain as a decentralized platform is so successful that many applications deployed on it. However, for the inherent transparency properties and the lack of privacy, deploying a financial application on top of it is always a challenge. In this paper, we tackle this challenge and propose an anonymous sealed-bid auction protocol based on time-released encryption atop Consortium Block chain. We adopt a strict digital certificate-based identity mechanism of the consortium block chain to permit legitimate participants, and utilize the blind signature based on elliptic curve technology to allowing anonymous participation. Moreover, a timed release public key encryption algorithm is adopted to encrypt bids and prevent auctioneer from colluding with bidders. This is completely different from the method (zero-knowledge proof) used in other papers to prevent collusion between auctioneer and bidder. We provide a specific analysis of our protocol, which shows that our protocol meets anonymity and applicability. KEYWORDS Consortium Block chain, Smart Contract, Sealed-Bid Auction, Time-Released Encryption, Blind signature
Parinya Ekparinya, Vincent Gramoli, Guillaume Jourjon
In this paper, we explore vulnerabilities and countermeasures of the recently proposed blockchain consensus based on proof-of-authority. The proof-of-work blockchains, like Bitcoin and Ethereum, have been shown both theoretically and empirically vulnerable to double spending attacks. This is why Byzantine fault tolerant consensus algorithms have gained popularity in the blockchain context for their ability to tolerate a limited number t of attackers among n participants. We formalize the recently proposed proof-of-authority consensus algorithms that are Byzantine fault tolerant by describing the Aura and Clique protocols present in the two mainstream implementations of Ethereum. We then introduce the Cloning Attack and show how to apply it to double spend in each of these protocols with a single malicious node. Our results show that the Cloning Attack against Aura is always successful while the same attack against Clique is about twice as fast and succeeds in most cases.
This article describes the structure and functionality of OpTrak, a decentralized app implemented using the Ethereum blockchain that targets the opioid epidemic currently plaguing the United States. Over-prescription and distribution of opioids cost the national healthcare system over $78 billion every year. Problems persist in every stage of the process, from doctors prescribing the medication to the pharmacists fulfilling prescriptions. These problems arise from a combination of factors, including lack of accountability, transparency, and reliability in the current prescription drug monitoring programs. This work provides three key contributions to research on a technical approach to mitigate the opioid epidemic. First, the authors pinpoint key problems in the current opioid prescription system. Second, they propose an integrated approach for addressing the problems by leveraging distributed ledgers, focusing on blockchain technology. Third, the authors describe the structure and functionality of OpTrak that allows a consortium of care providers to exchange patient prescription data securely.
Sam M. Werner, Paul J. Pritz, Alexei Zamyatin, William J. Knottenbelt
Mining pools in Proof-of-Work cryptocurrencies allow miners to pool their computational resources as a means of reducing payout variance. In Ethereum, uncle blocks are valid Proof-of-Work solutions which do not become the head of the blockchain, yet yield rewards if later referenced by main chain blocks. Mining pool operators are faced with the non-trivial task of fairly distributing rewards for both block types among pool participants.
Md. Nazmus Saadat, Syed Abdul Halim Syed Abdul Rahman, Rasheed Mohammad Nassr, Megat F. Zuhiri
Blockchain was only used as a foundation of cryptocurrency initially, but today, we can see the rise of this new emerging technology being implemented in many industries. In the future, most technologies around the world are expected to use blockchain as an efficient way to make online transactions. One of the areas that blockchain technologies can be applied is crowdfunding platforms. The most common problem with current crowdfunding scene in Malaysia (and around the world) is that the campaigns are not regulated and some of the crowd-funding campaign turned out to be fraud. Besides, the completion of some projects also was significantly delayed. This project aims to solve these problems by applying Ethereum smart contracts to the crowdfunding site to that the contracts will be fully automatically executed, thus preventing frauds and ensuring that the projects can be delivered within duration given.
This paper reports on the development of a formal symbolic process virtual machine (FSPVM) denoted as FSPVM-E for verifying the reliability and security of Ethereum-based services at the source code level of smart contracts, and a Coq proof assistant is employed for both programming the system and for proving its correctness. The current version of FSPVM-E adopts execution-verification isomorphism, which is an application extension of Curry-Howard isomorphism, as its fundamental theoretical framework to combine symbolic execution and higher-order logic theorem proving. The four primary components of FSPVM-E include a general, extensible, and reusable formal memory framework, an extensible and universal formal intermediate programming language denoted as Lolisa, which is a large subset of the Solidity programming language using generalized algebraic datatypes, the corresponding formally verified interpreter of Lolisa, denoted as FEther, and assistant tools and libraries. The self-correctness of all components is certified in Coq. Currently, FSPVM-E supports the ERC20 token standard, and can automatically and symbolically execute Ethereum-based smart contracts, scan their standard vulnerabilities, and verify their reliability and security properties with Hoare-style logic in Coq. To the best of authors' knowledge, the present work represents the first hybrid formal verification system implemented in Coq for Ethereum smart contracts that is applied at the Solidity source code level.
In recent years, blockchains have obtained so much attention from researchers, engineers, and institutions; and the implementation of blockchains has started to revive a large number of applications ranging from e-finance, e-healthcare, smart home, Internet of Things, social security, logistics and so forth. In the literature on blockchains, it is found that most articles focused on their engineering implementation, while little attention has been devoted to the exploration of theoretical aspects of the system; however, the existing work is limited to model the mining process only. In this paper, a queuing theory-based model is proposed for understanding the working and theoretical aspects of the blockchain. We validate our proposed model using the actual statistics of two popular cryptocurrencies, Bitcoin and Ethereum, by running simulations for two months of transactions. The obtained performance measures parameters such as the Number of Transactions per block, Mining Time of Each Block, System Throughput, Memorypool count, Waiting Time in Memorypool, Number of Unconfirmed Transactions in the Whole System, Total Number of Transactions, and Number of Generated Blocks; these values are compared with actual statistics. It was found that the results gained from our proposed model are in good agreement with actual statistics. Although the simulation in this paper presents the modeling of blockchain-based cryptocurrencies only, the proposed model can be used to represent a wide range of blockchain-based systems.
Christof Ferreira Torres, Mathis Steichen, Radu State
Modern blockchains, such as Ethereum, enable the execution of so-called smart contracts - programs that are executed across a decentralised network of nodes. As smart contracts become more popular and carry more value, they become more of an interesting target for attackers. In the past few years, several smart contracts have been exploited by attackers. However, a new trend towards a more proactive approach seems to be on the rise, where attackers do not search for vulnerable contracts anymore. Instead, they try to lure their victims into traps by deploying seemingly vulnerable contracts that contain hidden traps. This new type of contracts is commonly referred to as honeypots. In this paper, we present the first systematic analysis of honeypot smart contracts, by investigating their prevalence, behaviour and impact on the Ethereum blockchain. We develop a taxonomy of honeypot techniques and use this to build HoneyBadger - a tool that employs symbolic execution and well defined heuristics to expose honeypots. We perform a large-scale analysis on more than 2 million smart contracts and show that our tool not only achieves high precision, but is also highly efficient. We identify 690 honeypot smart contracts as well as 240 victims in the wild, with an accumulated profit of more than $90,000 for the honeypot creators. Our manual validation shows that 87% of the reported contracts are indeed honeypots.
In the last year we have seen a great deal of both academic and practical
interest in the topic of vulnerabilities in smart contracts, particularly those
developed for the Ethereum blockchain. In this paper we survey the 21,270
vulnerable contracts reported by six recent academic projects. Contrary to what
might have been believed given the reported number of vulnerable contracts,
there has been precious little in terms of actual exploitation when it comes to
these vulnerabilities. We find that at most 504 out of 21,270 contracts have
been subjected to exploits. This corresponds to at most 9,066 ETH (~1.8 million
USD), or only 0.29% of the 3 million ETH (600 million USD) claimed in some of
the papers. While we are certainly not implying that smart contract
vulnerability research is without merit, our results suggest that the potential
impact of vulnerable code had been greatly exaggerated.
In recent years, we have seen a great deal of both academic and practical interest in the topic of vulnerabilities in smart contracts, particularly those developed for the Ethereum blockchain. While most of the work has focused on detecting *vulnerable* contracts, in this paper, we focus on finding how many of these vulnerable contracts have actually been *exploited*. We survey the 23,327 vulnerable contracts reported by six recent academic projects and find that, despite the amounts at stake, only 1.98% of them have been exploited since deployment. This corresponds to at most 8,487 ETH (~1.7 million USD), or only 0.27% of the 3 million ETH (600 million USD) at stake. We explain these results by demonstrating that the funds are very concentrated in a small number of contracts which are *not exploitable* in practice.
The rise of smart contract systems such as Ethereum has resulted in a proliferation of blockchain-based decentralized applications including applications that store and manage a wide range of data. Current smart contracts are designed to be executed solely by miners and are revealed entirely on-chain, resulting in reduced scalability and privacy. In this paper, we discuss that scalability and privacy of smart contracts can be enhanced by splitting a given contract into an off-chain contract and an on-chain contract. Specifically, functions of the contract that involve high-cost computation or sensitive information can be split and included as the off-chain contract, that is signed and executed by only the interested participants. The proposed approach allows the participants to reach unanimous agreement off-chain when all of them are honest, allowing computing resources of miners to be saved and content of the off-chain contract to be hidden from the public. In case of a dispute caused by any dishonest participants, a signed copy of the off-chain contract can be revealed so that a verified instance can be created to make miners enforce the true execution result. Thus, honest participants have the ability to redress and penalize any fraudulent or dishonest behavior, which incentivizes all participants to honestly follow the agreed off-chain contract. We discuss techniques for splitting a contract into a pair of on/off-chain contracts and propose a mechanism to address the challenges of handling dishonest participants in the system. Our implementation and evaluation of the proposed approach using an example smart contract demonstrate the effectiveness of the proposed approach in Ethereum.
Open access
3 source records
Blockchain Technology Applications and Security
Cryptography and Data Security
Advanced Steganography and Watermarking Techniques
Smart contracts are programs running on top of blockchain platforms. They interact with each other through well-defined interfaces to perform financial transactions in a distributed system with no trusted third parties. But these interfaces also provide a favorable setting for attackers, who can exploit security vulnerabilities in smart contracts to achieve financial gain. This paper presents SmartScopy, a system for automatic synthesis of adversarial contracts that identify and exploit vulnerabilities in a victim smart contract. Our tool explores the space of \emph{attack programs} based on the Application Binary Interface (ABI) specification of a victim smart contract in the Ethereum ecosystem. To make the synthesis tractable, we introduce \emph{summary-based symbolic evaluation}, which significantly reduces the number of instructions that our synthesizer needs to evaluate symbolically, without compromising the precision of the vulnerability query. Building on the summary-based symbolic evaluation, SmartScopy further introduces a novel approach for partitioning the synthesis search space for parallel exploration, as well as a lightweight deduction technique that can prune infeasible candidates earlier. We encoded common vulnerabilities of smart contracts in our query language, and evaluated SmartScopy on the entire data set from etherscan with $>$25K smart contracts. Our experiments demonstrate the benefits of summary-based symbolic evaluation and show that SmartScopy outperforms two state-of-the-art smart contracts analyzers, Oyente and Contractfuzz, in terms of running time, precision, and soundness. Furthermore, running on recent popular smart contracts, SmartScopy uncovers 20 vulnerable smart contracts that contain the recent BatchOverflow vulnerability and cannot be precisely detected by existing tools.