Blockchain technology and its applications have played an important role to overcome challenges in numerous areas of the life. However, most current blockchain projects have concentrated on financial model by using existing platforms such as Bitcoin or Ethereum to generate tokens without the development of the technological features. Unfortunately, the decentralization has several challenges which cannot be adopted by our current political, economic and social systems. The fundamental technical problem of current blockchain algorithm is that `performance inefficiency' could not be solved, in comparison with the central server system. In addition, the client software cannot establish conventions for making decisions about the future direction of the cryptocurrency. Furthermore, users' completed anonymity and the absence of a responsible person are also open problems of decentralization. To this end, this paper proposes an alternative method, dubbed RCANE which is semi-centralized network of parallel blockchain and APoS (Authorized Proof of Stake), whose purpose is to solve the above challenges of current blockchain and comply with our preconceived perspectives of the current political, social, and economic systems to build up an ecosystem for economy, society and politics. Several experiments are conducted to show the executability of RCANE Project.
This paper addresses the problem of uploading large quantities of sensitive industrial data to a public distributed network by proposing a new framework. The framework combines the existing technologies of the distributed web and distributed ledger to provide a mechanism of encrypting data and choosing whom to share the data with. The framework is designed to work with existing platforms; the InterPlanetary File System (IPFS) and the Ethereum blockchain platforms are used as examples within this paper, though it is stated that similar platforms are capable of providing the requirements for the framework to operate. The framework uses the concept of the Diffie-Hellman Key Exchange (DHKE), and is implemented in three different mechanisms of the DHKE: one-step Elliptical-Curve Diffie-Hellman Key Exchange (ECDH); two-step ECDH; and Supersingular Isogeny Diffie-Hellman Key Exchange (SIDH). The paper discusses the security of each along with individual advantages and disadvantages, and concludes that the SIDH is the most appropriate implementation for future use due to it being post-quantum secure.
The healthcare industry is constantly reforming and adopting new shapes with respect to the technological evolutions and transitions. One of the crucial requirements in the current smart healthcare systems is the protection of patients sensitive data against the potential adversaries. Therefore, it is vital to have secure data access mechanisms that can ensure only authorized entities can access the patients medical information. Hence, this paper considers blockchain technology as a distributed approach protect the data in healthcare systems. This research proposes a blockchain based secure and efficient data accessibility mechanism for the patient and the doctor in a given healthcare system. Proposed system able to protect the privacy of the patients as well. The security analysis of our scheme shows that it can resist to well-known attacks along with maintaining the integrity of the system. Moreover, an Ethereum based implementation has used to verify the feasibility of our proposed system.
In the age of Big Data, enabling task scheduling while protecting users' privacy is critical for various decentralized applications in blockchain-based smart contract platforms. Such a privacy-preserving task scheduler requires the task input data to be secretly maintained until a prescribed task execution time and be automatically recorded into the blockchain to enabling the execution of the task at the execution time, even if the user goes offline. While straight-forward centralized approaches provide a basic solution to the problem, unfortunately they are limited to a single point of trust and involve a single point of control. This paper presents decentralized techniques for supporting privacy-preserving task scheduling using smart contracts in Ethereum blockchain networks. We design a privacy-preserving task scheduling protocol that is managed by a manager smart contract. The protocol requires a user to schedule a task by deploying a proxy smart contract maintaining the non-sensitive information of the task while creating decentralized secret trust and selecting trustees from the network to maintain the sensitive information of the task. With security techniques including secret sharing and layered encryption as well as security deposit paid by trustees as economic deterrence, the protocol can protect the sensitive information against possible attacks including some trustees destroying the sensitive information (drop attack) or secretly releasing the sensitive information before the execution time (release-ahead attack). We demonstrate the attack-resilience of the proposed protocol through rigorous analysis.Our implementation and experimental evaluation on the Ethereum official test network demonstrate the low monetary cost and the low time overhead associated with the proposed approach.
Cloud Service Level Agreement (SLA) is challengeable due to lacking a trustworthy platform. This paper presents a witness model to credibly enforce the cloud service level agreement. Through introducing the witness role and using the blockchain based smart contract, we solve the trust issues about who can detect the service violation, how the violation is confirmed and the compensation is guaranteed. In this model, a verifiable consensus sortition algorithm proposed by us is firstly leveraged to select independent witnesses to form a witness committee. They are responsible for a specific service level agreement and get paid by monitoring and detecting service violation. Through carefully designing the witness' payoff function in the agreement, we further leverage game theory to analyze and prove that it is not the witness itself is trustworthy. Instead, the witness has to tell the truth because of its greedy nature, which is the desire to maximize its own revenue. As long as the service violation is confirmed by the witness committee, the compensation is automatically transferred to the customer by the smart contract. Finally, we implement a proof-of-concept prototype with the smart contract of Ethereum blockchain. It demonstrates the feasibility of our model.
Blockchain technologies are rapidly gaining attention in the multi-agent systems (MAS) community to face critical issues such as trust, secured communications, and data consistency. In particular, the notion of smart contract can be exploited to deploy trustworthy computations automatically executed by the network in a consistent way. MAS coordination - modelling and engineering of agents interaction in a MAS - thus represents an appealing application field for smart contracts, potentially enabling fully-decentralised, trustworthy coordination. Along this line, we focus on the Ethereum blockchain technology, map it onto LINDA tuple-based coordination model, and discuss two proof-of-concept implementations of LINDA on Ethereum. We hence demonstrate conceptual and technical feasibility of blockchain-based coordination in MAS, while emphasising issues of applying the blockchain beyond accountability and identity management.
Various types of cryptocurrency e.g. BitCoin, Ethereum, Zcash, and more, are broadly accepted and used in many different forms of business but a typical problem that the cryptocurrency users are faced with is the delay of coin transfer. For example, it takes several hours for BitCoin and several minutes for Ethereum. These cryptocurrencies also consume a high quantity of electricity for transaction validation. Even though there currently is a type of cryptocurrencies, Ripple, that can be quickly transferred in 4 seconds but still it is a closed system with an owner, not a public cryptocurrency. Similarly, an algorithm "Proof of Stake" used by new coins that are more energy-saving but several problems are still found including (1) 51% attack, (2) a richer with more coins gains higher rewards, and (3) a problematic node for block validation that is not currently active. This research presents a model of an open cryptocurrency system that is able to transfer a coin within 3 seconds in which an algorithm called "Random-Checkers Proof of Stake" (RCPoS) was proposed to randomly select the inspectors for validation processes which can avoid those three problems of the Proof of Stake.
Blockchain Technology Applications and Security
Chaos-based Image/Signal Encryption
Advanced Steganography and Watermarking Techniques
Lars Pilgaard Mikkelsen, Kasper Mortensen, Henrik Rasmussen, Hans-Peter Schwefel · 5 authors
Usage of IoT marketplaces as central components in distributed systems have become common, as they allow for easy exploitation of other services and data sources. When relying on a marketplace to be available in order for a system to be operational, it is critical that the marketplace operation is highly robust. Marketplaces are typically centralized components which means that single point of failure is a possible issue. Also users of the marketplace must trust the operator to be fair and follow a common set of rules. This work proposes to utilize blockchain technology to realize a distributed marketplace where both functionalities and storage are distributed and thereby increasing availability to users, while removing the need for a central operator. The blockchain also makes the operational rules transparent to the users of the marketplace. In this relation two core marketplace functionalities, offering creation and discovery, are realized using smart contracts on a private Ethereum blockchain and evaluated using an experimental testbed. The results demonstrate the feasibility of a blockchain based marketplace implementation.
Nowadays, a combination between Internet of Things (IoT) technology and remote healthcare system is extensively researched due to its efficiency and convenience for human life. When the number of IoT devices in health care system is increased exponentially, the privacy and security issues of patients are becoming a concern. In order to protect personal and device-generated information, we propose to use blockchain-based smart contracts for managing patients' information and medical devices. In detail, using blockchain based on the Ethereum protocol, we create a remote healthcare system including healthcare provider (such as hospital), healthcare professionals (doctors) and patients. Health condition of patients is measured by sensors and such information is written into blockchain automatically. In addition, we propose a processing mechanism to store the medical device information efficiently and sparingly in accordance with health situation of patient. Concretely, we filter the data from sensors before deciding whether to write data into blockchain or not. Doing so we can reduce the size of blockchain as well as save amount of coins for transaction efficiently. However, the abnormal data from sensors will be written to blockchain immediately and trigger an emergency contact to doctor and hospital for on-time treatment. We have verified the proposed smart contract on Ethereum test environment called TESTRPC and implemented the system on an experimental environment with real devices. This system works well at small scale.
Blockchain is first introduced by Bitcoin in 2009 and developers all around the world have been trying to apply blockchain in different areas, like finance services, credit and ownership management, resource sharing, investment management, Internet of Things (IoT) etc. Ethereum is a Blockchain 2.0 platform that allows developers to build a Decentralized Application (DApp) without building a new blockchain from the scratch. IoT is the technology to embed all the physical devices with sensors and chips to provide automation process via machine-to-machine communication. Blynk is a platform that provides iOS and Android application for the users and developers to collect data from control microcontroller. This paper is aiming to build a system with Ethereum private Blockchain, Raspberry Pi (RPi), Blynk platform, DHT11 temperature and humidity sensors. The system is a proof-of-concept prototype to simulate smart home applications. It collects the real-time room temperature and humidity by DHT11 via Raspberry Pi. The sensor data will be updated to the Blynk App and stored on the smart contract deployed on the Ethereum private Blockchain. If the real-time temperature or humidity value exceeds the threshold value set by the users, red or green LEDs will be turned on as warnings. This system can be improved by some possible future work.
Xu Wang, Xuan F. Zha, Guangsheng Yu, Wei Ni · 8 authors
Ethereum, as the first Turing-complete blockchain platform, provides various application program interfaces for developers. Although blockchain has highly improved security, faulty configuration and usage can result in serious vulnerabilities. In this paper, we focus on the security vulnerabilities of the official Go-version Ethereum client (geth). The vulnerabilities are because of the insecure API design and the specific Ethereum wallet mechanism. We demonstrate attacks exploiting these vulnerabilities in an Ethereum testbed. The vulnerabilities are confirmed by the scanning results on the public Internet. Finally, corresponding countermeasures against attacks are provided to enhance the security of the Ethereum platform.
Quanqing Xu, Zhiwen Song, Rick Siow Mong Goh, Yongjun Li
Evolvement of blockchain technology has greatly changed the network and it makes many applications to be distributed, decentralized without loss of security. Ethereum is an open-source blockchain platform that provides a runtime environment for running smart contracts, which is called Ethereum Virtual Machine (EVM). Ethereum-based applications are usually referred to as Decentralized Applications (DApps), since they are based on the decentralized EVM, and its smart contracts. Meanwhile, distributed data store also evolves fast with the blockchain technology. Distributed storage develops to reduce the cost of the server side hardware and increase data availability. InterPlanetary File System (IPFS) is a protocol for distributed storage. IPFS stores immutable data, remove duplication, and obtain address information for storage nodes to search for files in the network. Many DApps have been created with the use of these technologies and one example is to use this design for a decentralized Twitter-like system that is resistant to censorship and single point of failure. This paper involves researching the blockchain technology and implementing a decentralised social network application on the Ethereum private blockchain with the use of smart contract and IPFS. In addition, it examines how blockchain and distributed storage can enable more functionalities of traditional social network systems.
IoT is leading a digital revolution in both academia and industry. It brings convenience to people's daily lives; however, the issues of security and privacy of IoT become challenges. Blockchain, a decentralized database based on cryptographic techniques, is promising for IoT security, which may influence a variety of areas including manufacture, finance, and trading. The blockchain framework in an IoT system is an intriguing alternative to the traditional centralized model, which is struggling to meet some specified demands in IoT. In this article, we investigate typical security and privacy issues in IoT and develop a framework to integrate blockchain with IoT, which can provide great assurance for IoT data and various functionalities and desirable scalability including authentication, decentralized payment, and so on. We also suggest some possible solutions to these security and privacy issues in IoT based on blockchain and Ethereum to show how blockchain contributes to IoT.
Blockchain Technology Applications and Security
IoT and Edge/Fog Computing
Advanced Steganography and Watermarking Techniques
Fatih Ceylan, Ramazan Eki̇nci̇, Osman Tüzün, Hakan Kahyaoğlu
Başta Bitcoin olmak üzere kripto paralar son dönemde çok sık kullanılmaya başlamıştır. “Para birimi” olarak ve “Değer birikim aracı” olarak kabul görmeye başlayan kripto paraların fiyat hareketlerinin analiz edilmesi ihtiyacı ortaya çıkmıştır. Bu piyasaların büyümesi ve küresel entegrasyonu ile birlikte fiyatlarda meydana gelen önemli değişimlerin temelinde spekülatif balonların olup olmadığı finansal istikrar konusunda açıklık ve güvence açısından önem arz etmektedir. Ayrıca kripto para piyasasında meydana gelen spekülatif hareketler piyasa katılımcılarının sürü psikolojisiyle hareket edip etmedikleri sorusunu ortaya çıkarmaktadır. Bu nedenle çalışmada Bitcoin ve Etherium para birimlerinde spekülatif balonların varlığı Philips vd. (2015) tarafından geliştirilen yöntem ile tespit edilmiş ve ne zaman oluştukları tahminlenmiştir. Piyasada balonların olması ve bu balonların süre olarak varlığı sürü psikolojisinin olduğu yönünde bilgi sağlarken, bu piyasada dengeleyici bir spekülasyonun olmadığı yönünde de bir bilgidir. Elde edilen bulgular doğrultusunda Bitcoin ve Etherium kripto para birimlerinde çok sayıda baloncuk olduğu tespit edilmiştir. Özellikle 2017-2018 yılları arasında büyük baloncukların ortaya çıkması bu para birimlerinin spekülatif hareketlere karşı eğilimli olduğunu gösterilmiştir.
We propose and compare two approaches to identify smart contracts as token systems by analyzing their public bytecode. The first approach symbolically executes the code in order to detect token systems by their characteristic behavior of updating internal accounts. The second approach serves as a comparison base and exploits the common interface of ERC-20, the most popular token standard. We present quantitative results for the Ethereum blockchain, and validate the effectiveness of both approaches using a set of curated token systems as ground truth. We observe 100% recall for the second approach. Recall rates of 89% (with well explainable missed detections) indicate that the first approach may also be able to identify "hidden" or undocumented token systems that intentionally do not implement the standard. One possible application of the proposed methods is to facilitate regulator' tasks of monitoring and policing the use of token systems and their underlying platforms.
Hans‐Arno Jacobsen, Mohammad Sadoghi, Mohammad Hossein Tabatabaei, Roman Vitenberg · 5 authors
Known for powering cryptocurrencies such as Bitcoin and Ethereum, blockchain is seen as a disruptive technology capable of revolutionizing a wide variety of domains, ranging from finance to governance, by offering superior security, reliability, and transparency founded upon a decentralized and democratic computational model. In this tutorial, we first present the original Bitcoin design, along with Ethereum and Hyperledger, and reflect on their design choices through the academic lens. We further provide an overview of potential applications and associated research challenges, as well as a survey of ongoing research directions related to byzantine fault-tolerance consensus protocols. We highlight the new opportunities blockchain creates for building the next generation of secure middleware platforms and explore the possible interplay between AI and blockchains, or more specifically, how blockchain technology can enable the notion of "decentralized intelligence." We conclude with a walkthrough demonstrating the process of developing a decentralized application using a popular Smart Contract language (Solidity) over the Ethereum platform
The cryptocurrency is attracting more and more attention because of the blockchain technology. Ethereum is gaining a significant popularity in blockchain community, mainly due to the fact that it is designed in a way that enables developers to write smart contracts and decentralized applications (Dapps). There are many kinds of cryptocurrency information on the social network. The risks and fraud problems behind it have pushed many countries including the United States, South Korea, and China to make warnings and set up corresponding regulations. However, the security of Ethereum smart contracts has not gained much attention. Through the Deep Learning approach, we propose a method of sentiment analysis for Ethereum's community comments. In this research, we first collected the users' cryptocurrency comments from the social network and then fed to our LSTM + CNN model for training. Then we made prediction through sentiment analysis. With our research result, we have demonstrated that both the precision and the recall of sentiment analysis can achieve 0.80+. More importantly, we deploy our sentiment analysis1 on RatingToken and Coin Master (mobile application of Cheetah Mobile Blockchain Security Center23). We can effectively provide detail information to resolve the risks of being fake and fraud problems.
Auction is an effective way to allocate goods or services to bidders who value them the most. The rapid growth of e-auctions facilitates online transactions but poses new and distinctive challenges. It is difficult to establish trust among sellers, buyers, and auctioneers without centralized auction websites or platforms (the auctioneer) which collect bids and derive the auction results. However, these third parties may be untrustworthy, and malicious sellers or buyers may refuse to deliver the goods or payment according to the protocol. Moreover, the open and anonymous online environment may stimulate auction participants to form collusion coalitions to rig the auction and reap unfair profit. Many auction designs have been proposed to address these concerns, but they fall short of simultaneously achieving decentralization (i.e., held without a trusted third utility), strong consensus (i.e., the establishment of trust), collusion resistance, and practical implementation. We present CReam, the first decentralized collusion-resistant e-auction system that is implemented with smart contract on the blockchain. With the carefully designed smart auction contract, mutually distrustful and rational sellers and buyers are stimulated to operate properly, hence transact safely without trusted third parties. The auction mechanism in the smart contract can effectively prevent bidder collusion and realize economic robustness, i.e., truthfulness. We implement a fully functional CReam on the Ethereum network. Extensive experimental results confirm that CReam can greatly reduce the probability of collusion and achieve an approximate optimal revenue at a low cost of contract execution.
Elvira Albert, Pablo Gordillo, Albert Rubio, Ilya Sergey
Gas is a measurement unit of the computational effort that it will take to execute every single operation that takes part in the Ethereum blockchain platform. Each instruction executed by the Ethereum Virtual Machine (EVM) has an associated gas consumption specified by Ethereum. If a transaction exceeds the amount of gas allotted by the user (known as gas limit), an out-of-gas exception is raised. There is a wide family of contract vulnerabilities due to out-of-gas behaviours. We report on the design and implementation of GASTAP, a Gas-Aware Smart contracT Analysis Platform, which takes as input a smart contract (either in EVM, disassembled EVM, or in Solidity source code) and automatically infers sound gas upper bounds for all its public functions. Our bounds ensure that if the gas limit paid by the user is higher than our inferred gas bounds, the contract is free of out-of-gas vulnerabilities.
Elvira Albert, Pablo Gordillo, Albert Rubio, Ilya Sergey
Gas is a measurement unit of the computational effort that it will take to execute every single operation that takes part in the Ethereum blockchain platform. Each instruction executed by the Ethereum Virtual Machine (EVM) has an associated gas consumption specified by Ethereum. If a transaction exceeds the amount of gas allotted by the user (known as gas limit), an out-of-gas exception is raised. There is a wide family of contract vulnerabilities due to out-of-gas behaviours. We report on the design and implementation of GASTAP, a Gas-Aware Smart contracT Analysis Platform, which takes as input a smart contract (either in EVM, disassembled EVM, or in Solidity source code) and automatically infers sound gas upper bounds for all its public functions. Our bounds ensure that if the gas limit paid by the user is higher than our inferred gas bounds, the contract is free of out-of-gas vulnerabilities.
Muhammad Ahmad Zafar, Falak Sher, Muhammad Umar Janjua, Salman Baset
Could smart contracts written in Solidity, a popular language among blockchain developers for Ethereum, be run on other blockchain platforms such as Hyperleger Fabric. To run Solidity smart contracts on another blockchain platform, one can either incorporate the Ethereum Virtual Machine (EVM) in the target blockchain, or perform a source-to-source translation of the Solidity contracts to a smart contract language for the target platform. This paper presents Sol2js, an open source source-to-source translation tool that generates Javascript smart contracts for Hyperledger Fabric from Solidity contracts, and provides a conceptual mapping of Ethereum constructs to that of Hyperleger Fabric, where possible. Presently, the tool is able to successfully translate 65-70% of Solidity constructs including major types, functions, inheritance, and events. The preliminary results show that the average of the lines of code (loc) across translated contracts is 7.5x more than the average of Solidity contracts loc while preserving contract semantics.
Aditya M. Deshpande, Pezhman Nasirifard, Hans‐Arno Jacobsen
Cryptocurrencies and Distributed Ledger Technologies, such as Ethereum have received extensive attention over the past few years. With the increasing popularity of Ethereum, comprehensive understanding of its various properties plays a critical role in the widespread adaptation. However, due to the significant requirements for deploying a full Ethereum blockchain and high running costs, it is challenging to study the dynamic properties of the Ethereum. In this work, we propose eVIBES, a configurable simulation framework for gaining empirical insights into the dynamic properties of Ethereum.
The success and growing popularity of blockchain technology has lead to a significant increase in load on popular permissionless blockchains such as Ethereum. With the current design, these blockchain systems do not scale with additional nodes since every node executes every transaction. Further efforts are therefore necessary to develop scalable permissionless blockchain systems.
Blockchains yield to new workloads in database management systems and K/V-Stores. Distributed Ledger Technology (DLT) is a technique for managing transactions in 'trustless' distributed systems. Yet, clients of nodes in blockchain networks are backed by 'trustworthy' K/V-Stores, like LevelDB or RocksDB in Ethereum, which are based on Log-Structured Merge Trees (LSM-Trees). However, LSM-Trees do not fully match the properties of blockchains and enterprise workloads.