The increasing adoption of multi-cloud computing has created new opportunities for improving resource utilization, service reliability, and reducing dependence on a single cloud provider. However, the distributed nature of multi-cloud infrastructures introduces significant challenges in maintaining data security, privacy, and continuous service availability. This study presents a dynamic security framework designed for multi-cloud environments that integrates adaptive monitoring with a multi-layer encryption mechanism. The proposed approach intelligently selects suitable encryption techniques based on data sensitivity, file size, and available computing resources to achieve an optimal balance between security and performance. The framework Dynamic Resource Management Algorithm(DRMA) for secure key establishment, efficient symmetric encryption for protecting data, and zero-knowledge proof-based authentication to ensure secure user verification without revealing sensitive information. A comprehensive performance evaluation was conducted by comparing the proposed model with conventional RSA-based security approaches. Experimental results demonstrate improved computational efficiency, reduced encryption overhead, enhanced scalability, and stronger protection against unauthorized access. Furthermore, the framework provides resilience against both conventional cyberattacks and emerging quantum computing threats while maintaining efficient resource utilization. These findings indicate that the proposed solution offers a practical and secure approach for protecting data and improving the reliability of modern multi-cloud environments.
Devdoot Maji, Ravi Singh Lamkoti, Hitesh Shetty, Bharati Gondhalekar
An estimated 26.3 million students enrolled in Indian higher education in 2018-19 and nearly 9 million graduates annually. A student, whether he is a high school student or an undergraduate, or maybe a postgraduate, generates a lot of certificates that may include results, diplomas, or transcripts during this entire duration of studies. For admission, students need to produce these certificates in institutions or companies. Tracking these certificates and validating their authenticity manually becomes a tedious job. The absence of an appropriate anti-forge system leads to a scenario where it is found that the graduation certificate is forged. To make the data more secure and safe, everything needs to be digitalized with the principle of Confidentiality, Reliability, and Availability. All of these can be achieved with a technology named Blockchain. Briefly, the flow of our system will consist of a Certificate issuer who will generate certificates and those certificates will be validated by a panel within that organization before being sent to a student. Each certificate will have a unique hash key which can be used to validate the authenticity of the certificate by any organization through the portal. The benefit of such a system is that the student also faces less risk of losing or damaging a certificate and the validation of the certificate can also be done quite easily.
First, a big data analysis of the transactions and smart contracts made on\nthe Ethereum blockchain is performed, revealing interesting trends in motion.\nNext, these trends are compared with the public's interest in Ether and\nBitcoin, measured by the volume of online searches. An analysis of the crypto\nprices and search trends suggests the existence of big players (and not the\nregular users), manipulating the market after a drop in prices. Lastly, a\ncross-correlation study of crypto prices and search trends reveals the pairs\nproviding more accurate and timely predictions of Ether prices.\n
The cloud-fog-edge hybrid system is the evolution of the traditional centralized cloud computing model. Through the combination of different levels of resources, it is able to handle service requests from terminal users with a lower latency. However, it is accompanied by greater uncertainty, unreliability, and instability due to the decentralization and regionalization of service processing, as well as the unreasonable and unfairness in resource allocation, task scheduling, and coordination, caused by the autonomy of node distribution. Therefore, this paper introduces blockchain technology to construct a trust-enabled interaction framework in a cloud-fog-edge environment, and through a double-chain structure, it improves the reliability and verifiability of task processing without a big management overhead. Furthermore, in order to fully consider the reasonability and load balance in service coordination and task scheduling, Berger’s model and the conception of service justice are introduced to perform reasonable matching of tasks and resources. We have developed a trust-based cloud-fog-edge service simulation system based on iFogsim, and through a large number of experiments, the performance of the proposed model is verified in terms of makespan, scheduling success rate, latency, and user satisfaction with some classical scheduling models.
Hossam Saad Shady Yasser Hassan Gaber Aya Samy, Ashraf Tammam, Ahmed Fahmy, Bahaa Hasan
Blockchain is one of the most powerful and promising technologies nowadays in the IT industry, One of Blockchain’s main features is the presence of a Consensus Algorithm, which is responsible for maintaining the security and integrity of the entire blockchain network where all the nodes participating in the network reach a certain agreement. However, some algorithms like the Proof-of-Work require very high energy consumption to reach a single agreement by solving a puzzle and provides a low throughput (3-7 transactions/second), thus, it may not be very reliable in blockchain solutions. In this paper, we aim to provide a reliable choice for different business use-cases by proposing a modification in the Istanbul Byzantine Fault Tolerance voting-based algorithm that provides a higher throughput (up to 1140 tx/s), which will be very important to be used in the use case called a letter of credit which is a part of trade finance (relation between exporter, importer and the bank institutions).
Distributed energy, mainly composed of new energy, plays an important role in promoting the development of new energy. At present, the development of distributed energy is greatly hindered by imperfect trading platform and unstable output of new energy. Blockchain is decentralized, autonomous and requires collaborative management. Its own technical characteristics have the inherent advantages of reconstructing the energy system. The alliance chain in the blockchain is more suitable for building a distributed energy trading platform. The paper constructs a distributed energy transaction model based on alliance blockchain, studies the integration mode of blockchain and distributed energy transaction, and explores the application of blockchain in distributed transaction. The paper provides a new idea for optimizing and reconstructing the traditional distributed energy trading platform, and providing decision support for promoting distributed energy trading.
Since the introduction of the first Bitcoin blockchain in 2008, different\ndecentralized blockchain systems such as Ethereum, Hyperledger Fabric, and\nCorda, have emerged with public and private accessibility. It has been widely\nacknowledged that no single blockchain network will fit all use cases. As a\nresult, we have observed the increasing popularity of multi-blockchain\necosystem in which customers will move toward different blockchains based on\ntheir particular requirements. Hence, the efficiency and security requirements\nof interactions among these heterogeneous blockchains become critical. In\nrealization of this multi-blockchain paradigm, initiatives in building\nInteroperability-Facilitating Platforms (IFPs) that aim at bridging different\nblockchains (a.k.a. blockchain interoperability) have come to the fore. Despite\ncurrent efforts, it is extremely difficult for blockchain customers\n(organizations, governments, companies) to understand the trade-offs between\ndifferent IFPs and their suitability for different application domains before\nadoption. A key reason is due to a lack of fundamental and systematic\napproaches to assess the variables among different IFPs. To fill this gap,\ndeveloping new IFP requirements specification and open-source benchmark tools\nto advance research in distributed, multi-blockchain interoperability, with\nemphasis on IFP performance and security challenges are required. In this\ndocument, we outline a research proposal study to the community to realize this\ngap.\n
It is said that blockchain will contribute to the digital transformation of society in a wide range of ways, from the management of public and private documents to the traceability in various industries, as well as digital currencies. A number of so-called blockchain platforms have been developed, and experiments and applications have been carried out on them. But are these platforms really conducive to practical use of the blockchain concept? To answer the question, we need to better understand what the technology called blockchain really is. We need to sort out the confusion we see in understanding what blockchain was invented for and what it means. We also need to clarify the structure of its applications. This document provides a generic model of understanding blockchain and its applications. We introduce design patterns to classify the platforms. We categorize possible use cases by identifying the structure among applications, and organize the functional, performance, operational and legal requirements for each such case. Based on the categorization and criteria, we evaluated and compared the following platforms: Hyperledger Fabric, Hyperledger Iroha, Hyperledger Indy, Ethereum, Quorum/Hyperledger Besu, Ethereum 2.0, Polkadot, Corda and BBc-1. We have tried to be fair in our evaluations and comparisons, but we also expect to provoke discussion. The intended readers for this document is anyone involved in development of application systems who wants to understand blockchain and their platforms, including non-engineers and non-technologists. The assessments in this document will allow readers to understand the technological requirements for the blockchain platforms, to question existing technologies, and to choose the appropriate platforms for the applications they envision. The comparisons hopefully will also be useful as a guide for designing new technologies.
Cryptocurrencies like Bitcoin and Ethereum, are widely known applications of blockchain technology, have drawn much attention and are largely recognized in recent years. Initially Bitcoin and Ethereum processed 7 and 15 Transactions Per Second (TPS) respectively, whereas VISA and Paypal process 1700 and 193 TPS respectively. The biggest challenge to blockchain adoption is scalability, defined as the capacity to change the block size to handle the growing amount of load. This paper attempts to present the existing scalability solutions which are broadly classified into three layers: Layer 0 solutions focus on optimization of propagation protocol for transactions and blocks, Layer 1 solutions are based on the consensus algorithms and data structure, and Layer 2 solutions aims to decrease the load of the primary chain by implementing solutions outside the chain. We present a classification and comparison of existing blockchain scalability solutions based on performance along with their pros and cons
Rafael Belchior, André Vasconcelos, Miguel Correia, Thomas Hardjono
The emergence of blockchain interoperability is reducing the risk of investing in blockchain by avoiding vendor lock-in, leveraging interoperation, and providing migration capabilities. However, to fully unlock the internet of blockchains, it is necessary to provide enterprise interoperability mechanisms that allow service providers to comply with different regulations, e.g., data privacy regulations. Each blockchain can be reached via a gateway, allowing to interconnect value, to provide different services, and to enable self-sovereignty. To realize this vision, we propose Hermes, a fault-tolerant middleware that connects blockchain networks and is based on the Open Digital Asset Protocol (ODAP). Hermes is crash fault-tolerant by allying a new protocol, ODAP-2PC, with a log storage API that can leverage blockchain to secure logs, providing them transparency, auditability, availability, and non-repudiation. We introduce a use case benefiting from Hermes, digital cross-jurisdiction promissory notes. We show that cross-chain transactions can be achieved securely with Hermes, given that gateways are complying with legal frameworks.
This paper presents libtxsize, a library to estimate the size requirements of arbitrary Bitcoin transactions. To account for different use cases, the library provides estimates in bytes, virtual bytes, and weight units. In addition to all currently existing input, output, and witness types, the library also supports estimates for the anticipated Pay-to-Taproot transaction type, so that estimates can be used as input for models attempting to quantify the impact of Taproot on Bitcoin's scalability. libtxsize is based on analytic models, whose credibility is established through first-principle analysis of transaction types as well as exhaustive empirical validation. Consequently, the paper can also serve as reference for different Bitcoin data and transaction types, their semantics, and their size requirements (both from an analytic and empirical point of view).
Wei Yao, Fadi P. Deek, Renita Murimi, Guiling Wang
Consensus algorithms are central to blockchain technology and an emerging research area. In this paper, we begin with an overview of the different types and architectures of blockchain networks. Then, with a focus on consortium blockchains, we survey, classify, and assess their principal consensus mechanisms. Furthermore, as consensus mechanisms determine network reliability, enhance performance efficiency, and ensure system security, we conduct a critical analysis of the strengths and weaknesses of consensus algorithms using a taxonomy of three different criteria: reliability, performance, and security. We conclude with insights into current and future research challenges and opportunities in this domain.
Blockchain is a distributed ledger that is decentralized, immutable, and transparent, which maintains a continuously growing list of transaction records ordered into blocks. As the core of blockchain, the consensus algorithm is an agreement to validate the correctness of blockchain transactions. For example, Bitcoin is a public blockchain where each node in Bitcoin uses the Proof of Work (PoW) algorithm to reach a consensus by competing to solve a puzzle. Unlike a public blockchain, a consortium blockchain is an enterprise-level blockchain that does not contend with the issues of creating a resource-saving global consensus protocol. This paper highilights several state-of-the art solutions in consensus algorithms for enterprise blockchain. For example, the HyperLedger by Linux Foundation includes implementing Practical Byzantine Fault Tolerance (PBFT) as the consensus algorithm. PBFT can tolerate a range of malicious nodes and reach consensus with quadratic complexity. Another consensus algorithm, HotStuff, implemented by Facebook Libra project, has achieved linear complexity of the authenticator. This paper presents the operational mechanisms of these and other consensus protocols, and analyzes and compares their advantages and drawbacks.
By design, distributed ledger technologies persist low-level data which makes conducting complex business analysis of the recorded operations challenging. Existing blockchain visualization and analytics tools such as block explorers tend to rely on this low-level data and complex interfacing to provide enriched level of analytics. The ability to derive richer analytics could be improved through the availability of a higher level abstraction of the data. This article proposes an abstraction layer architecture that enables the design of high-level analytics of distributed ledger systems and the decentralized applications that run on top. Based on the analysis of existing initiatives and identification of the relevant user requirements, this work aims to establish key insights and specifications to improve the auditability and intuitiveness of distributed ledger systems by leveraging the development of future user interfaces. To illustrate the benefits offered by the proposed abstraction layer architecture, a regulated sector use case is explored.
Hyperledger Fabric (HLF), one of the most popular permissioned blockchains, has recently received attention for blockchain-enabled Internet of Things (IoT). However, for IoT applications to handle time-sensitive data, the processing latency in HLF has emerged as a new challenge. In this article, therefore, we establish a practical HLF latency model for HLF-enabled IoT. We first discuss the structure and the transaction flow of HLF-enabled IoT. After implementing real HLF, we capture the latencies that each transaction experiences and show that the total latency of HLF can be modeled as a Gamma distribution, which is validated by conducting a goodness-of-fit test (i.e., the Kolmogorov-Smirnov (KS) test). We also provide the parameter values of the modeled latency distribution for various HLF environments. Furthermore, we explore the impacts of three important HLF parameters including the average transaction generation rate, block size, and block-generation timeout on the HLF latency. As a result, this article provides design insights on minimizing the average latency for HLF-enabled IoT.
Throughput performance is a critical issue in blockchain technology, especially in blockchain sharding systems. Although sharding proposals can improve transaction throughput by parallel processing, the essence of each shard is still a small blockchain. Using serial execution of smart contract transactions, performance has not significantly improved, and there is still room for improvement. A smart contract concurrent execution strategy based on concurrency degree optimization is proposed for performance optimization within a single shard. This strategy is applied to each shard. First, it characterizes the conflicting contract feature information by executing a smart contract, analyzing the factors that affect the concurrent execution of the smart contracts, and clustering the contract transaction. Second, in shards with high transaction frequency, considering the execution time, conflict rate, and available resources of contract transactions, finding a serializable schedule of contract transactions by redundant computation and a Variable Shadow Speculative Concurrency Control (SCC-VS) algorithm for smart contract scheduling is proposed. Finally, experimental results show that the strategy increases the concurrency of smart contract execution by 39% on average and the transaction throughput of the whole system by 21% on average.
Carlos Melo, Jamilson Dantas, Paulo Pereira, Paulo Maciel
Blockchain and Cloud Computing are two of the main topics related to the distributed computing paradigm, and in the last decade, they have seen exponential growth in their adoption. Cloud computing has long been established as the main mechanism to test, develop, and deliver new applications and services in a distributed manner across the World Wide Web. Large data centers host many services and store petabytes of user data. Infrastructure and services owners rule the access to data and may even be able to change contents and attest to its veracity. Blockchain is a step towards a future where the user's data are considered safer, besides being public. Advances in blockchain-based technologies, now, support service provisioning over permissioned and private infrastructures. Therefore, organizations or groups of individuals may share information, service even if they do not trust each other, besides supporting infrastructure management tasks. This paper presents and evaluates models for assessing the availability and capacity-oriented availability of cloud computing infrastructures. It aims at running Blockchain's distributed applications based on the Ethereum blockchain platform and the required expenses to perform service delivery in public and private infrastructures. Most of the obtained results also apply to other blockchains based platforms.
Blockchain-based Distributed Ledgers (DLs) promise to transform the existing financial system by making it truly democratic. In the past decade, blockchain technology has seen many novel applications ranging from the banking industry to real estate. However, in order to be adopted universally, blockchain systems must be scalable to support a high volume of transactions. As we increase the throughput of the DL system, the underlying peer-to-peer network might face multiple levels of challenges to keep up with the requirements. Due to varying network capacities, the slower nodes would be at a relative disadvantage compared to the faster ones, which could negatively impact their revenue. In order to quantify their relative advantage or disadvantage, we introduce two measures of network fairness, $p_f$, the probability of frontrunning and $α_f$, the publishing fairness. We show that as we scale the blockchain, both these measures deteriorate, implying that the slower nodes face a disadvantage at higher throughputs. It results in the faster nodes getting more than their fair share of the reward while the slower nodes (slow in terms of network quality) get less. Thus, fairness and scalability in blockchain systems do not go hand in hand. In a setting with rational miners, lack of fairness causes miners to deviate from the "longest chain rule" or undercut, which would reduce the blockchain's resilience against byzantine adversaries. Hence, fairness is not only a desirable property for a blockchain system but also essential for the security of the blockchain and any scalable blockchain protocol proposed must ensure fairness.
Fátima Leal, Adriana E. Chis, Horacio González–Vélez
Multi-service networks aim to efficiently supply distinct goods within the same infrastructure by relying on a (typically centralised) authority to manage and coordinate their differential delivery at specific prices. In turn, final customers constantly seek to lower costs whilst maximising quality and reliability. This paper proposes a decentralised business model for multi-service networks using Ethereum blockchain features – gas, transactions, and smart contracts – to execute multiple services at different prices. By employing the Ethereum cryptocurrency token, Ether, to quantify the quality of service and reliability of distinct private Ethereum networks, our model concurrently processes streams of services at different gas prices while differentially delivering reliability and service quality. This multi-service business model has been extensively tested on five concurrent Ethereum networks with various combinations of gas prices, miners, and regular nodes using a Proof of Authority consensus algorithm and throughput as the evaluation metric. It has exhibited linear scalability, providing increased throughput in high-quality Ethereum networks, i.e., composed of more validator nodes. The results also indicate that different mining prices do not impact the network performance, but networks with more miners had limited scalability and an increased level of trustworthiness and reliability.
In recent years, blockchain has grown in popularity due to its singular attributes, enabling the development of new innovative decentralized applications. But when companies consider leveraging blockchain for their applications, the plethora of possible choices and the difficulty of integrating blockchain into architectures can hinder its adoption. Our research project aims to ease the adoption of blockchain into companies, notably with the construction of an automated decision process to solve this issue in which requirements are first-class citizens, a knowledge base containing architectural patterns and blockchains refined over time, and an architecture generator able to process outputs into architectural stubs. This paper will also present our current progression on this decision process, by introducing the preliminary version that is able to choose the most suitable blockchain between multiple choices and our process-driven benchmarking tool.
Sivleen Kaur, Sheetal Chaturvedi, Aabha Sharma, Jayaprakash Kar
The concept of blockchain, widely known as virtual currencies, saw a massive surge in popularity in recent times. As far as the security of the blockchain is concerned, consensus algorithms play a vital role in the blockchain. Research has been done separately, or comparisons between a few of them have been presented previously. In this paper, we have discussed widely used consensus algorithms in the blockchain. The consensus protocols covered in this paper include PoW (Proof of Work), PoS (Proof of Stake), DPoS (Delegated Proof of Stake), PoET (Proof of Elapsed Time), PBFT (Practical Byzantine Fault Tolerance), and PoA (Proof of Authority). For each consensus, we have reviewed the properties, applications, and performance in the blockchain.
Among the hot research topics, Fintech is leading the trend in terms of the newest technology applications. The relatively new emerging paradigms in various sciences, such as geometry (fractals), physics (quantum), and database systems (distributed ledger—blockchain), seem to potentially contribute to a greater shift in the framework of the finance industry, bringing also some concerns (cyber-threats). Consistent and extensive investigation of the reasonable potential impact of these new models (and their underlying technologies) is performed, and then tested through a SWOT analysis, as the main objective of this research. Threats and opportunities are always intrinsically driven by the introduction of technological advancements (revolutions). This research confirms that information availability and the increasing interconnection of crosswise applications of each discovery to the different fields of science is determining the rapid succession of revolutions identified by evident large shifts in economic paradigms. The growing computing capacity and the development of increasingly powerful predictive software are leading to a competitive, extremely dynamic, and challenging system. In this context, as shown by history, there is a high possibility of market concentration in which, however, only a few corporations—digital giants—can afford to develop these technologies, consolidating their dominance.