Youcef Djenouri, Gautam Srivastava, Asma Belhadi, Jerry ChunâWei Lin
Abstract This article introduces a new problem of distributed knowledge graph, in IoT 5G setting. We developed an endâtoâend solution for solving such problem by exploring the blockchain management and intelligent method for producing the better matching of the concepts and relations of the set of knowledge graphs. The concepts and the relations of the knowledge graphs are divided into several components, each of which contains similar concepts and relations. Instead of exploring the whole concepts and the relations of the knowledge graphs, only the representative of these components is compared during the matching process. The framework has outperformed stateâofâtheâart knowledge graph matching algorithms using different scenarios as input in the experiments. In addition, to confirm the usability of our suggested framework, an inâdepth experimental analysis has been done; the results are very promising in both runtime and accuracy.
Emerging multitenant cloud computing ecosystems allow multiple applications to share virtualized pool of computing and networking resources. As a result, such ecosystems are becoming increasingly prone to data privacy concerns (personal data leakages and unauthorized access). While cloud computing providers support robust security and privacy mechanisms (e.g., public key cryptography, firewalls, and virtual private networks, among many others), they lack mechanisms and frameworks to monitor, audit, and verify these data privacy concerns. The emergence of data protection regulations around the world, such as General Data Protection Regulation in Europe and the Data Protection Act in the U.K., further emphasizes the need to overcome these privacy limitations. In this article, a novel technique for monitoring, auditing, and verifying the operations carried out on a userâs personal data in cloud computing ecosystems is proposed. Our research methodology leverages distributed ledger technologies (e.g., blockchain and smart contracts) for developing an immutable recording technique, which transparently logs, monitors, and verifies the operations carried out on user data. Using a healthcare pharmacy scenario and extensive real-world experiments, we validate the feasibility of the proposed technique. The proposed work handles a large pool of requests ($>$13K) ensuring minimal latency ($\approx$50â60 ms) and overheads for three different service packages varied with respect to the number of actors and operations.
Angtai Li, Guohua Tian, Meixia Miao, Jianpeng Gong
In cloud storage, public auditing is a more popular data integrity verification technique since it allows users to delegate auditing tasks to a fully trusted third-party auditor (TPA). However, it is difficult to find such a TPA in practical application. Besides, the centralised auditing model makes TPA have to bear burdensome work pressure, which limits the practicability of existing schemes. In this paper, we firstly proposed a blockchain-based generalised shared auditing mechanism BCSA in the cross-user scenario, which aims at achieving available public auditing with a non-fully trusted TPA, and reducing the user's auditing fees and TPA's work pressure by allowing data users to share their auditing procedure with others. Furthermore, we initialise a concrete construction BCSAD with DiffieâHellman protocol for the cross-user auditing scenario with different data. Likewise, we also propose a novel construction BCSAI for the cross-user auditing scenario with identical data, which utilises a password-authenticated key exchange (PAKE) protocol to achieve shared auditing and ciphertext deduplication, reducing data storage and auditing fees for data users and alleviating service pressure on the cloud server and TPA. Security and performance analysis evaluate the practicability of the proposed scheme.
Archives, both analogue and digital, are primarily concerned with preserving records as originals. Because of this, immutable data as used in a blockchain data structure seem a logical choice when designing such systems. At the same time, archives maintain records which may need to change over the long term. It is a requirement of archival preservation to be able to update recordsâ metadata in order not only to guarantee authenticity after digital preservation actions but also to ensure that relationships to other records, which might be created after an original record has entered the archive (and has been registered in a blockchain), can be maintained. The need to maintain an archival bond, which represents a network of relationships between aggregation of records, i.e., the relationship connecting previous and subsequent records belonging to the same activity, is a prime example of this requirement. This paper explores realisation of the archival bond in the context of blockchain-based archival system by proposing a supporting database system which enables metadata to be changed as required but also significantly simplifies searching compared to searching on-chain information, while keeping the immutability characteristic of blockchain.
Paolo Bellavista, Christian Esposito, Luca Foschini, Carlo Giannelli · 6 authors
Blockchain technology plays a pivotal role in the undergoing fourth industrial revolution or Industry 4.0. It is considered a tremendous boost to company digitalization; thus, considerable investments in blockchain are being made. However, there is no single blockchain technology, but various solutions exist, and they cannot interoperate with one each other. The ecosystem envisioned by the Industry 4.0 does not have centralized management or leading organization, so a single blockchain solution cannot be imposed. The various organizations hold their own blockchains, which must interoperate seamlessly. Despite some solutions for blockchain interoperability being proposed, the problem is still open. This paper aims to devise a secure solution for blockchain interoperability. The proposed approach consists of a relay scheme based on Trusted Execution Environment to provide higher security guarantees than the current literature. In particular, the proposed solution adopts an off-chain secure computation element invoked by a smart contract on a blockchain to securely communicate with its peered counterpart. A prototype has been implemented and used for the performance assessment, e.g., to measure the latency increase due to cross-blockchain interactions. The achieved and reported experimental results show that the proposed security solution introduces an additional latency that is entirely tolerable for transactions. At the same time, the usage of the Trusted Execution Environment imposes a negligible overhead.
Tri Wahyuningsih, Gunawan Gunawan, Fitra Putri Oganda, Mey Anggraeni
With the approaching of the digital age, digital education resources bring convenience to folks as a result of they're liable to duplicate and spread, however there are some disadvantages in on-line education service transactions. The safety problems with digital education resources and also the development of smuggled distribution seriously harm the rights and interests of the house owners of digital education resources. supported this, during this paper, we have a tendency to planned a blockchain-based digital education resources authentication system that uses the decentralized, tamper-resistant options of blockchain technology to store the digital education resources info within the style of a secret text. Within the system, there is no have to be compelled to need the participation of any third-party institution. The system planned during this study can greatly defend the rights and interests of the owner of digital education resources.
The global supply chain is a network of interconnected processes that create, use, and exchange records, but which were not designed to interact with one another. As such, the key to unlocking the full potential of supply chain management (SCM) technologies is achieving interoperability across participating records systems and networks. We review existing research and solutions using distributed ledger technology (DLT) and provide a survey of its current state of practice. We additionally propose a holistic solution: a DLT-based interoperable future state that could enable the interoperable, efficient, reliable, and secure exchange of records with integrity. Finally, we provide a gap analysis between our proposed future state and the current state, which also serves as a gap analysis for many fractional DLT-based SCM solutions and research.
Document verification is a complex domain that involves processes to authenticate original documents. Some original documents like birth certificate, university diploma, contract, certificate of occupancy, Will etc. may involve serious verification and authentication practices, because fake documents can easily be created. A skillfully generated fake document is always difficult to detect and can be treated as original. With the increase of forged documents, the integrity of both the document holder and the issuing authority is jeopardized. This research is intended to address the issue of electronic document forgery and provide an alternative secure means for storing documents. The aim of this research is to design and implement a secure document verification system using blockchain. The result of this study shows how the user documents are stored securely in the blockchain, and if any change or adjustment are made to the documents the chain becomes invalid and the user will be notified
Abstract Signed information is difficult to manage and this difficulty is even bigger when pieces of signed digital information have to be exchanged in an atomic procedure. Multiparty contract signing is an application of fair exchange of values, where the information to be exchanged are signed versions of a contract. Traditionally, this trust service requires the involvement of a trusted third party (TTP). This is a point of weakness for the generalization of the use of electronic contract signing protocols. Another usual problem for multiparty contract signing is that the protocols for multiparty exchanges are far more complex that those for two-party exchanges. Additionally, it is common that the signers demand protocols that assure the confidentiality of the contract. In this proposal blockchain-based technologies and smart contracts are used to obtain a protocol for electronic contract signing that does not need a TTP in any stage of the procedure. The protocol satisfies the ideal requirements for the contract signing service, even allowing the signature of confidential contracts. Moreover, the proposed solution is far more efficient than previous solutions for fair exchange protocols using blockchain presented up to the date thanks to the use of elliptic curve cryptography.
A flexible and effective identity system scheme has always been one of the core needs of the information age. Traditional centralized public key infrastructure has a number of flaws, and the present distributed public key infrastructure based on blockchain has a number of issues with performance, resilience, non-repudiation, identity flexibility, and other factors. This paper innovatively combines blockchain with decentralized undeniable attribute-based signatures and proposes a novel distributed public key infrastructure, which uses threshold algorithms and attribute-based signatures for fine-grained management of identities; the paper also introduces non-interactive zero-knowledge proof to make the certificate undeniable and uses the blockchain consensus mechanism to synchronize the certificate library to achieve distributed identity authentication. Through experimental modeling and analysis combined with specific scenarios' actual landing demand, this article indicates that the solution is adequate in terms of security and usability.
Forensic Science includes scientific methods to find out the actual cause of a crime and to bring justice to the victims. Forensic reports incorporate information regarding different crimes. These details are considered as extremely valuable and confidential as it helps the law enforcement agencies and prosecutors to ensure punishment to the blameworthy persons. These reports require security only to restrict access to the authorized persons. Blockchain stores every transaction occurring in the system and these transactions cannot be removed or modified because of their immutability. In this work, Inter-Planetary File System (IPFS) and Hyperledger based private blockchain are assembled to implement a secure forensic information storing system. Our system enables the tracing of any illegitimate en-trance or data tempering by the intruders. Our proposed hybrid approach surpasses the classical public blockchain systems i.e. Bitcoin and Ethereum in terms of transaction processing time achieving an average of 11.99 seconds per transaction. This system also facilitates the storing of heavyweight features which is not possible inside the existing blockchain frameworks.
The increased use of cloud computing technology and its wide adoption in the software industry has led to almost all modern consumer services being heavily dependent on the performance of the computing resources provided by the Cloud Service Provider (CSP). SLA which is agreed upon by both users and the CSP, plays a key role in keeping the performance of provisioned resources above a certain threshold. This SLA is enforced by CSP who uses the logs generated by the underlying machinery to monitor the performance of the machines and compensate the user. Similarly, a cautious customer might maintain its own monitoring mechanism to continuously evaluate the performance of the virtualized resources allocated to them. This creates distrust between the CSP and the client as both of them might not acknowledge the credibility of the other's monitoring mechanism and come at disagreement with each other on this. In this work, we propose a framework for SLA-violation detection and compensation using Hyperledger Fabric blockchain. Furthermore, we carry out the scalability and efficiency analysis Hyperledger Fabric network for the proposed system.
The past few years have seen a spate of cyber attacks targeting multinational companies, governments, institutions and even individuals' data. Most of these attacks target the vulnerabilities of the centralized system of data storage, emphasizing that a novel approach to data storage must be developed to tackle long-standing issues with centralized systems. Blockchain technology - a decentralized ledger based system provides a viable alternative to many of these issues. The objective of this paper was to develop and test a decentralized document storage system using a private Blockchain network, Ethereum coins and the InterPlanetary File System(IPFS). Interim results suggested that the proposed solution can be implemented at scale for certain use cases including confidential documents of both private and public entities.
Edge computing emerges as an alternative to cloud computing in the scenarios where the end devices require lower latency and faster access speeds. Edge nodes are deployed at the proximity of the end devices to reduce response time. On the other hand, the edge nodes are usually owned by small organizations that have limited operations and maintenance capabilities. Data on the edge may be easily damaged, due to external attacks or internal hardware failures. Therefore, it is essential to verify data integrity in edge computing. However, edge environment requires a different trust model compared with other computing and storage paradigm. Besides, compared with cloud storage, edge storage is decentralized and storage service participants may pose greater internal and external threats. This paper proposes a blockchain-based intelligent crowdsourcing audit approach (Crowdauditing) to achieve on-chain and off-chain credibility of audit results. The model relies on an untrusted auditor committee from the crowd to audit data integrity and uses smart contracts as the core of the intelligent system to ensure the reliability of result submission, the accuracy of the result judgment, and reasonable punishments and rewards. Specifically, an unbiased selection algorithm is proposed to achieve fairness during the auditor committee construction. An innovative two-stage submission strategy is proposed to ensure that the auditor committee can reach a consensus on the off-chain audit results. An incentive mechanism is carefully designed to force auditors providing audit services honestly to maximize their own rewards. Moreover, we modeled that as a game of n players, which proves the reliability of the result. Finally, we implement a prototype of Crowdauditing based on smart contracts. The extensive experimental results demonstrate the effectiveness of Crowdauditing.
Christian DelgadoâvonâEitzen, Luis Anido, Manuel J. FernĂĄndez Iglesias
Blockchain technologies are attracting the interest of different actors in various sectors and, among them, the education field, which is also studying how to apply these technologies to improve the traceability, accountability, and integrity of its information. Although different initiatives and projects were launched and are being developed, there are still issues not fully resolved, such as privacy, compliance with data protection regulations and scalability. This research proposes a novel design of a system to issue, store and verify different types of academic information, which allows complying with applicable regulations, protecting the privacy of users' personal data, as well as addressing the problem of scalability and performance.
Most of the existing identity systems are built on top of centralized storage systems. Storing identity data on these types of centralized storage platforms(e.g cloud storage, central servers) becomes a major privacy concern since various types of attacks and data breaches can happen. With this research, we are proposing blockchain and self-sovereign identity based digital identity (KYC - Know Your Customer) platform âCasperâ to address the issues on centralized identity systems. âCasper â is an Android/iOS based mobile identity wallet application that combines the integration of blockchain and a self-sovereign identity-based approach. Unlike centralized identity systems, the actual identities of the customer/users are stored in the customersâ mobile wallet application. The proof of these identities is stored in the blockchain-based decentralized storage as a self-sovereign identity proof. Casper platformsâ Self-Sovereign Identity(SSI)-based system provides a Zero Knowledge Proof(ZKP) mechanism to verify the identity information. Casper platform can be adopted in various domains such as healthcare, banking, government organization etc. As a use case, we have discussed building a digital identity wallet for banking customers with the Casper platform. Casper provides a secure, decentralized and ZKP verifiable identity by using blockchain and SSI based approach. It addresses the common issues in centralized/cloud-based identity systems platforms such as the lack of data immutability, lack of traceability, centralized control etc.
In recent years, as blockchain adoption has been expanding across a wide range of domains, e.g., digital asset, supply chain finance, etc., the confidentiality of smart contracts is now a fundamental demand for practical applications. However, while new privacy protection techniques keep coming out, how existing ones can best fit development settings is little studied. Suffering from limited architectural support in terms of programming interfaces, state-of-the-art solutions can hardly reach general developers. In this paper, we proposed the CLOAK framework for developing confidential smart contracts. The key capability of Cloak is allowing developers to implement and deploy practical solutions to multi-party transaction (MPT) problems, i.e., transact with secret inputs and states owned by different parties by simply specifying it. To this end, CLOAK introduced a domain-specific annotation language for declaring privacy specifications and further automatically generating confidential smart contracts to be deployed with trusted execution environment (TEE) on blockchain. In our evaluation on both simple and real-world applications, developers managed to deploy business services on blockchain in a concise manner by only developing CLOAK smart contracts whose size is less than 30% of the deployed ones.
Xiaoqiang Sun, F. Richard Yu, Peng Zhang, Zhiwei Sun · 6 authors
Blockchain, which is usually regarded as a public, decentralized and distributed ledger, has attracted significant attention recently. In the environment of blockchain, all historical transaction data are recorded and stored. However, because blockchain is open and transparent, a malicious user may illegally access private transaction data, including transaction amount, account address, and account balance. As a cryptographic technique, zero-knowledge proof (ZKP) can be used to verify whether the prover has enough transaction amount in the environment of blockchain without leaking any private transaction data. This article provides a comprehensive survey on ZKP in the environment of blockchain with the aim of highlighting security problems and challenges. It first discusses the framework, models and applications of ZKP. Next, it provides an introduction of blockchain, and proposes a framework of ZKP in the environment of blockchain. Then, it highlights the current state of ZKP in the environment of blockchain. Finally, it identifies some potential problems and future research directions.
The technological advancement and growth of the cloud computing technologies is changing network service provisioning and operation. Cloud based services represented as XaaS where X refers to service offering such as Platform, Software and Infrastructure as a service, provides flexible on-demand provisioning along with its security concerns that goes with the adoption of the cloud computing. Despite all the advantages of adopting the cloud computing option, the security and privacy of the clientsâ data cannot be overlooked. Understanding these security concerns is a fundamental requirement to choosing the cloud solution. This paper focuses on the use of Blockchain technology to mitigate the security challenges of the cloud computing. Literature reviews have discussed other security options for the cloud, but little discussions have centered on the adoption of the Block Chain technology to secure the cloud and open doors for future research of cloud computing using smart contract. Keywords: Blockchain, Distributed Database Systems, Data Integrity, cryptography, Cloud Infrastructure Security, Confidentiality, Distributed Ledger
management by introducing decentralized, immutable, and transparent ledgers. At the heart of blockchain's robustness lies its cryptographic foundation, which ensures data integrity, authenticity, and security. This paper delves into the cryptographic techniques employed in blockchain systems to enhance data integrity. We explore fundamental mechanisms such as hash functions, digital signatures, and Merkle trees, as well as advanced methods like zero-knowledge proofs and homomorphic encryption. By analyzing these techniques, we aim to provide a comprehensive understanding of how cryptography fortifies blockchain against data tampering and unauthorized access.
Alexandre Pinheiro, Edna Dias Canedo, Robson de Oliveira Albuquerque, Rafael T. de Sousa
The management practicality and economy offered by the various technological solutions based on cloud computing have attracted many organizations, which have chosen to migrate services to the cloud, despite the numerous challenges arising from this migration. Cloud storage services are emerging as a relevant solution to meet the legal requirements of maintaining custody of electronic documents for long periods. However, the possibility of losses and the consequent financial damage require the permanent monitoring of this information. In a previous work named "Monitoring File Integrity Using Blockchain and Smart Contracts", the authors proposed an architecture based on blockchain, smart contract, and computational trust technologies that allows the periodic monitoring of the integrity of files stored in the cloud. However, the experiments carried out in the initial studies that validated the architecture included only small- and medium-sized files. As such, this paper presents a validation of the architecture to determine its effectiveness and efficiency when storing large files for long periods. The article provides an improved and detailed description of the proposed processes, followed by a security analysis of the architecture. The results of both the validation experiments and the implemented defense mechanism analysis confirm the security and the efficiency of the architecture in identifying corrupted files, regardless of file size and storage time.
Intuitively there is a drastic distinction between the pure decentralized block-chain systems like Defis and those that only utilize block-chain as an enhancing technology but remain centralized with real-world business model and conventional technologies like database, application server, etc. Our study explores extensively this distinction from a methodological point of view, classifies them into blockchain-complete and blockchain-partial, analyzes key features of the two types, and reveals the root cause of this distinction. We analyze the function or, in more strong words, the "ultimate purpose" of blockchain in the blockchain-partial systems, and present a conceptual model we named proof-chain that quite satisfactorily represented the general paradigm of blockchain in blockchain-partial systems. A universal tension between strength of proof-chain and privacy is then revealed and the zero-knowledge based proof-chain takes shape. Several case studies demonstrate the explaining power of our proof-chain methodology. We then apply proof-chain methodology to the analysis of the ecosystem of a collaborating group of blockchain-partial systems, representing the paradigm of public and private data domain whose border the proof-chain crosses. Finally, some derived guidelines from this methodology speak usefulness of our methodology.