Lukas König, Yuliia Korobeinikova, Simon Tjoa, Peter Kieseberg
Since the introduction of Bitcoin, the term “blockchain” has attracted many start-ups and companies over the years, especially in the financial sector. However, technology is evolving faster than standardization frameworks. This left the industry in the position of having to use this emerging technology, without being backed by any international standards organization regarding for neither the technology itself, nor for a blockchain specific information security framework. In times of the General Data Protection Regulation and growing international trade conflicts, protecting information is more relevant than ever. Standardization of blockchains is an appeal to raise the development of information technologies to the next level. Therefore, this paper shall provide an overview of standardization organization’s publications about blockchains/distributed ledger technologies, a set of comparison criteria for future work and a comparison of the existing standards work itself. With that information, aligning to existing standardization efforts becomes easier, and might even present the possibility to create frameworks where there are none at the moment.
Beyond an emerging popular web applications runtime supported in almost all commodity browsers, WebAssembly (WASM) is further regarded to be the next-generation execution environment for blockchain-based applications. Indeed, many popular blockchain platforms such as EOSIO and NEAR have adopted WASM-based execution engines. Most recently, WASM has been favored by Ethereum, the largest smart contract platform, to replace the state-of-the-art EVM. However, whether and how well current WASM outperforms EVM on blockchain clients is still unknown. This article conducts the first measurement study to understand the performance on WASM VMs and EVM for executing smart contracts for blockchain-based applications. To our surprise, the current WASM VM does not provide expected satisfactory performance. The overhead introduced by WASM is really non-trivial. Our results shed the light on challenges when deploying WASM in practice, and provide insightful implications for improvement space.
The Distributed Ledger Technology (DLT) is a peer-to-peer model of sharing data among collaborating parties in a decentralized manner. An example of DLT is a blockchain where data form blocks in an append-only chain. Software architecture description usually comprises multiple views. The paper concentrates on the Deployment view of the DLT solution within the 1+5 architectural views model. The authors have proposed Unified Modeling Language (UML) extensibility mechanisms to describe the needed additional semantic notation to model deployment details. The paper covers both the network and node levels. The proposed stereotypes and tagged values have enriched UML Deployment diagram. We have gathered those modeling elements in dedicated UML Profile for Distributed Ledger Deployment. We have applied the profile to model Deployment view of a renewable energy management system that uses R3 Corda framework. The system records information about inbound and outbound energy to/from renewable energy grid.
Nowadays audit profession is faced with an excessive evolution of the information and communication technology (ICT). The effects of ICT on auditing are dual. On the one hand, auditing is faced with the digitalization of companies’ business operations, and on the other, auditors must be able to adapt their methodologies to these changes in order to be able to audit implemented ICT in the companies’ business operations. One of the latest ICT innovations includes the application of blockchain technology (BCT) in different business operations of a company, which represents the object of auditing. In order to audit BCT, auditors must apply appropriate audit procedures, whereas analytical procedures (APs) represent the most useful one. The subjects of this paper are external and internal auditors, and their application of APs for auditing implemented BCT in the companies’ business operations, in Croatia. Therefore, the main objective of this paper is to investigate the differences in the APs’ application and its usefulness for auditing BCT, as an emerging ICT, between external and internal auditors. To investigate the main objective of the paper, desk research and survey research were conducted. Overall results indicated that external and internal auditors in Croatia are aware that auditing BCT requires the application of advanced APs, for what they need to possess excellent knowledge about APs and BCT. Obtained results showed that auditors in Croatia possess below-average knowledge about APs and BCT. Therefore, the necessity for specialized education of external and internal auditors is inevitable. Regarding the investigation of differences in the readiness to audit BCT between external and internal auditors in Croatia, the results confirmed that external auditors are more ready to audit BCT than internal auditors. Finally, research results confirmed that the application of advanced APs in audit engagements will increase the efficiency and effectiveness of companies’ business operations supported by the BCT.
Abstract Background Blockchain technology has gained a great public interest due to the appearance of cryptocurrencies, a digital asset used for exchanging funds. Although blockchain calculations offer the benefits of security and reduced costs, blockchain is still strongly criticised for its lack of usefulness and resource-heavy consumption. Objectives The aim of this research is to provide different insights into blockchain technology and to propose NP-complete problems as a suitable alternative to the current consensus algorithm. Methods/approach This research discusses the current state of proposed alternatives, projects such as distributed volunteering for scientific purposes and different consensus algorithms within cryptocurrencies but focusing on incorporating NP-complete problems as a secondary, more useful option. Results Using the properties of NP-complete problems, it is possible to solve various problems in different areas, such as science, biology, medicine and finance, but also to improve business processes, optimize markets, payments and supply chains while decreasing environmental costs. Conclusions This paper shows that the alternative mechanisms are being developed and used to substitute an existing Blockchain algorithm with a more efficient one. It also suggests further investigation in this area because the alternatives greatly improve blockchain’s usability and efficiency.
We establish the optimal security threshold for the Bitcoin protocol in terms of adversarial hashing power, honest hashing power, and network delays. Specifically, we prove that the protocol is secure if [ra < 1/Δ0 + 1/rh,,] where rh is the expected number of honest proof-of-work successes in unit time, ra is the expected number of adversarial successes, and no message is delayed by more than Δ0 time units. In this regime, the protocol guarantees consistency and liveness with exponentially decaying failure probabilities. Outside this region, the simple private chain attack prevents consensus. Our analysis immediately applies to any Nakamoto-style proof-of-work protocol; in the full version of this paper we also present the adaptations needed to apply it in the proof-of-stake setting, establishing a similar threshold there.
Superlight clients enable the verification of proof-of-work-based blockchains by checking only a small representative number of block headers instead of all the block headers as done in simplified payment verification (SPV). Such clients can be embedded within other blockchains by implementing them as smart contracts, allowing for cross-chain verification. One such interesting instance is the consumption of Bitcoin data within Ethereum by implementing a Bitcoin superlight client in Solidity. While such theoretical constructions have demonstrated security and efficiency in theory, no practical implementation exists. In this work, we put forth the first practical Solidity implementation of a superlight client which implements the NIPoPoW superblocks protocol. Contrary to previous work, our Solidity smart contract achieves sufficient gas-efficiency to allow a proof and counter-proof to fit within the gas limit of a block, making it practical. We provide extensive experimental measurements for gas consumption. The optimizations that enable gas-efficiency heavily leverage a novel technique which we term hash-and-resubmit, which almost completely eliminates persistent storage requirements, the most expensive operation of smart contracts in terms of gas. Instead, the contract asks contesters to resubmit data and checks their veracity by hashing it. Other optimizations include off-chain manipulation of proofs in order to remove expensive look-up structures, and the usage of an optimistic schema. We show that such techniques can be used to bring down gas costs significantly and may be of independent interest. Lastly, our implementation allows us to calculate concrete cryptoeconomic parameters for the superblocks NIPoPoWs protocol and in particular to make recommendations about the monetary value of the collateral parameters. We provide such parameter recommendations over a variety of liveness settings.
João Paulo de Brito Gonçalves, Roberta Lima Gomes, Rodolfo da Silva Villaça, Esteban Municio · 5 authors
Service Level Agreements (SLAs) are used to establish a contract, an agreement between two parties, which can be between two operators, or between a customer and an operator. The SLAs methods are a key aspect between consumers and providers, which can continuously monitor the Quality of Service (QoS) attributes and enforce its reliability, but the SLA also needs an entity to manage it. Smarts contracts are programs that are executed in a blockchain and ensure integrity and reliability to data stored in the distributed structure. This work proposes a solution using smarts contracts and blockchains in order to simplify the process of SLA validation.
Xiangjun Zhang, Weiguo Wu, Shiyuan Yang, Xiong Wang
Driven by advanced 5G cellular systems, mobile edge computing (MEC) has emerged as a promising technology that can meet the energy efficiency and latency requirements of IoT applications. Edge service migration in the MEC environment plays an important role in ensuring user service quality and enhancing terminal computing capabilities. Application services on the edge side should be migrated from different edge servers to edge nodes closer to users, so that services follow users and ensure high-quality services. In addition, during the migration process, edge services face security challenges in an edge network environment without centralized management. To tackle this challenge, this paper innovatively proposes a blockchain-based security edge service migration framework, Falcon, which uses mobile agents different from VM and container as edge service carriers, making migration more flexible. Furthermore, we considered the dependencies between agents and designed a service migration algorithm to maximize the migration benefits and obtain better service quality. In order to ensure the migration of edge services in a safe and reliable environment, Falcon maintains an immutable alliance chain among multiple edge clouds. Finally, the experimental results show that “Falcon” has lower energy consumption and higher service quality.
William Pourmajidi, Lei Zhang, John Steinbacher, Tony Erwin · 5 authors
Service Level Agreements (SLA) are employed to ensure the performance of Cloud solutions. When a component fails, the importance of logs increases significantly. All departments may turn to logs to determine the cause of the issue and find the party at fault. The party at fault may be motivated to tamper with the logs to hide their role. We argue that the critical nature of Cloud logs calls for immutability and verification mechanism without the presence of a single trusted party. This article proposes such a mechanism by describing a blockchain-based log storage system, called Logchain, which can be integrated with existing private and public blockchain solutions. Logchain uses the immutability feature of blockchain to provide a tamper-resistance platform for log storage. Additionally, we propose a hierarchical structure to address blockchains’ scalability issues. To validate the mechanism, we integrate Logchain into Ethereum and IBM Blockchain. We show that the solution is scalable and perform the analysis of the cost of ownership to help a reader select an implementation that would address their needs. The Logchain's scalability improvement on a blockchain is achieved without any alteration of blockchains’ fundamental architecture. As shown in this work, it can function on private and public blockchains and, therefore, can be a suitable alternative for organizations that need a secure, immutable log storage platform.
Pingcheng Ruan, Tien Tuan Anh Dinh, Qian Lin, Meihui Zhang · 6 authors
The success of Bitcoin and other cryptocurrencies bring enormous interest to blockchains. A blockchain system implements a tamper-evident ledger for recording transactions that modify some global states. The system captures the entire evolution history of the states. The management of that history, also known as data provenance or lineage, has been studied extensively in database systems. However, querying data history in existing blockchains can only be done by replaying all transactions. This approach is feasible for large-scale, offline analysis, but is not suitable for online transaction processing. We present LineageChain, a fine-grained, secure, and efficient provenance system for blockchains. LineageChain exposes provenance information to smart contracts via simple interfaces, thereby enabling a new class of blockchain applications whose execution logics depend on provenance information at runtime. LineageChain captures provenance during contract execution and stores it in a Merkle tree. LineageChain provides a novel skip list index that supports efficient provenance queries. We have implemented LineageChain on top of Hyperledger Fabric and a blockchainoptimized storage system called ForkBase. We conduct extensive evaluation, demonstrating benefits of LineageChain, its efficient querying, and its small storage overhead.
João Henrique Faes Battisti, Maurício A. Pillon, Guilherme Koslovski, Charles C. Miers
A considerable number of electronic transaction systems employ classicapproaches based on centralized trust mechanisms, not exploitingthe latest technological advances. Alternatively, the concept ofblockchain stands out, elaborated without the need for this centralizedtrust, but rather dependent on securely chained technologies in whichthe elements involved can conduct secure negotiations. Blockchain isdesigned to address security and distributed system issues through theuse of encryption, algorithms, P2P networks, and consensus mechanisms.This paper presents a Denial of Service (DoS) security analysisof the more traditional Practical Byzantine Fault Tolerance (PBFT)and Proof of Work (PoW) consensus mechanisms available onMultichain and Ethereum solutions based on a private / consortiumblockchain scenario. We present our results of a controlled DoSattack, revealing the importance and need for security-relatedanalysis of blockchain implementations of private / consortiumblockchains.
Pol Alemany, Ricard Vilalta, Raül Muñoz, Ramon Casellas · 5 authors
This paper presents a non-hierarchical architecture to deploy End-to-End Network Slices in a multi-domain network using an Ethereum-based Blockchain to manage the Network Slicing requests across domains. The use of Blockchain aims to look towards a collaboration vision to deploy Networks Slices using the resources to deploy them as if they would be placed under the domain of the Network Slice requester. The authors describe a possible instantiation procedure and they present results showing how much the use of Blockchain might increase the deployment time of an End-to-End Network Slice.
In the present scenario, it is vital for any organization, especially the financial organizations, to understand customers and their financial dealings better. KYC is a process to verify identity and related details of corresponding customers. The current KYC mechanism has a severe concern in financial institutions as it requires separate ledger for the separate financial organizations. Every institution has its KYC process, which sometimes may include third-party, which may cause increased maintenance cost, time and redundancy. There is considerable wastage of costs in the form of opportunity cost, maintenance cost, customer verification cost and many more of around $27 million according to an economic survey. The current KYC process is very time-consuming, and it decreases the user experience. We have proposed an enhanced KYC system using blockchain technology to improve the existing KYC system. An inherent feature of the DLT is used to remove the third-party involvement, and smart contracts are used to build our logic in the mobility of the data. Blockchain technology has various types of cryptographic security which provide a safer place to transact over an unsecured channel. Using the facility of DLT, cryptography and consensus mechanism of blockchain, the proposed model of KYC process can optimize storing, updating, sharing of data and accessing operations along with enhanced security, transparency and privacy. It also enhances customer ownership and improves customer experience. It not only reduces the time duration and document update problem but also saves opportunity cost, aggregation, cost, maintenance cost and many more costs, which can affect the performance of any organization.
This article proposes a self-organizing collaborative computing network with an approach to enhance the expectation of a collaborating node for joining the self-organizing network. The proposed approach relies on Ethereum cryptocurrency and Smart Contract to enhance the expectation of collaborating nodes by monetizing the services provided to the self-organizing network. Furthermore, an escrow based smart contract is formalized in the proposed framework to sustains the monetary trust issue between collaborating nodes. The proposed scheme can enforce an autonomic incentive management mechanism to any type of self-organizing networks such as self-organizing clouds, ad-hoc networks, self-organizing federated cloud networks, self-organizing federated learning networks, and self-organizing D2D networks to name a few. Considering the distributed nature of these self-organizing networks and the Ethereum blockchain network, a distributed agent-based methodology is materialized in the proposed framework. Following this, a proof of concept implementation for the general case of a self-organizing cloud is presented. Lastly, the article provides some insights into possible future directions using the proposed framework.
As the use of online transaction is increasing day by day, the security measure parameter is difficult to manage. In that case, Blockchain enables peer-to-peer transfer of digital assets without any intermediaries in a secure manner with the use of verification and validation operation by different miner nodes of decentralized network. Blockchain technology also supports cryptocurrencies like
bitcoin and ethereum for amount transfer digitally with secure communication.
Voltage controls the majority of the processes around us, starting from\nlighting an incandescent lamp to running huge machines in industries.\nTherefore, voltage monitoring becomes essential, which demands efficient\nmeasurement and storage of voltage data. However, there is hardly any system\ntill date that fulfils both the goals of voltage monitoring and voltage data\nstorage. To achieve this goal, we propose the application of the Internet of\nThings along with the server-based framework and Distributed Ledger Technology\nto build systems for smart voltage monitoring. Two models - a centralised model\nand a decentralised model have been presented and analysed thoroughly in this\npaper. The centralised model is built on client-server architecture, whereas\nthe decentralised model is based on a peer-to-peer architecture. Blockchain and\nInterPlanetary File System have been used for the implementation of the\ndecentralised system. Potential improvements to make these systems robust have\nalso been discussed. The methods proposed in this paper for voltage monitoring\nare novel; ensure efficient data storage and can be used for IoT data storage\nof any form.\n
The traceable execution of business processes and choreographies using smart contracts is one prominent application of blockchain technology in Business Process Management (BPM). Existing approaches support a large set of patterns, modeling languages, and blockchain architectures, which cover a wide range of practical scenarios. However, they largely neglect the important aspect of time, a crucial part of process and choreography models manifested in deadlines, delays, and other temporal constraints. We argue that this deficit is due to inherent limitations of smart contracts---in particular the absence of a natural notion of measuring time---on popular blockchain platforms used in research and practice. We introduce a set of time measures available on blockchain platforms to alleviate these issues, and systematically compare their properties. We also give hints as to their suitability for facilitating various temporal constraints commonly found in process models.
With the advent of Bitcoin, the interest of the database community in blockchain systems has steadily grown. Many existing blockchain applications use blockchains as a platform for monetary transactions, however. We deviate from this philosophy and present ResilientDB, which can serve in a suite of non-monetary data-processing blockchain applications. Our ResilientDB uses state-of-the-art technologies and includes a novel visualization that helps in monitoring the state of the blockchain application.
This paper presents a PhD research plan that focuses on solving existing problems in requirements engineering, by means of a novel blockchain-enabled framework. Requirements engineering in general and requirements traceability in particular are characterized by a variety of distributed stakeholders and heterogeneity of tools. These characteristics introduce integration, communication, coordination and trust issues and impede the accurate and trustworthy traceability of requirements. Thereby, this paper proposes blockchain technology for the trustworthy management and traceability of requirements throughout the software development life cycle.
Sharding is a promising blockchain scaling solution. But it currently suffers from high latency and low throughput when it comes to cross-shard transactions, i.e., transactions that require coordination from multiple shards. The root cause of these limitations arise from the use of the classic two-phase commit protocol, which involves locking assets for extended periods of time. This paper presents Rivet, a new paradigm for blockchain sharding that achieves lower latency and higher throughput for cross-shard transactions. Rivet has a single reference shard running consensus, and multiple worker shards maintaining disjoint states and processing a subset of transactions in the system. Rivet obviates the need for consensus within each worker shard, and as a result, tolerates more failures within a shard and lowers communication overhead. We prove the correctness and security of Rivet. We also propose a more realistic framework for evaluating sharded blockchains by creating a benchmark based on real Ethereum transactions. An evaluation of our prototype implementation of Rivet and the baseline two-phase commit, atop 50+ AWS EC2 instances, using our evaluation framework demonstrates the latency and throughput improvements for cross-shard transactions.
A blockchain is a distributed ledger forming a distributed consensus on a history of transactions, and is the underlying technology for the Bitcoin cryptocurrency. Its applications are far beyond the financial sector. The transaction verification process for cryptocurrencies is much slower than traditional digital transaction systems. One approach to scalability or the speed at which transactions are processed is to design a solution that offers faster Proof of Work. In this paper, we propose a method for accelerating the process of Proof of Work based on parallel mining rather than solo mining. The goal is to ensure that no more than two or more miners put the same effort into solving a specific block. The proposed method includes a process for selection of a manager, distribution of work and a reward system. This method has been implemented in a test environment that contains all the characteristics needed to perform Proof of Work for Bitcoin and has been tested, using a variety of case scenarios, by varying the difficulty level and number of validators. Experimental evaluations were performed locally and in a cloud environment, and experimental results demonstrate the feasibility the proposed method.