In this article we present the technological foundations on which an ecosystem of semantic data objects can be implemented on the latest Blockchain based systems. As the most important citizens among the semantic data objects are ontologies, the ecosystem is referred to as Ontospace. The foundations can be characterized by their architectural, cryptographic and transactional aspects. The architectural aspect borrows from the latest Layer-2 protocols of the 3rd generation blockchains and from the rules of Linked Data systems creation. The cryptographic aspect represents an original work that attempts to resolve the issue of efficient hashing of the graph data structures. The transactional aspect is concerned with the graph replication consistency, conditions for the direct access to graph data from the blockchain smart-contracts and with linkage between sidechains bearing semantic objects and the main network. The large parts of the work were implemented in the context of the Ontochain project â a part of the Next Generation Internet EU Initiative.
As the popularity of e-commerce grows, an electronic coupon (e-coupon) is widely used due to its convenience and portability. In most e-coupon services, the information of e-coupons is managed on a centralized server. However, e-coupon services are often vulnerable to security issues because of centralization. For example, when the e-coupon information which is stored in a centralized e-coupon server is forged, it becomes difficult to match the user and the e-couponâs owner, and an expired e-coupon can be used repetitively (i.e., double-spending). To handle this issue, we propose a new e-coupon service by exploiting a blockchain system to improve the security of the service. To do this, we first design a server to enable the e-coupon service and communicate with the blockchain system. Second, we devise a smart contract on the blockchain system to provide integrity of the e-coupon business logic and the e-couponâs information. We implemented the proposed service on an Ethereum-based blockchain system. The experimental results show that our proposed service improves higher security with a minor performance overhead compared with an existing e-coupon service.
M. Sumathi, N. Vijayaraj, S. P. Raja, Venkatachalapathy Maharajan
HIGHLIGHTS The permissioned blockchain is used for resource allocation and monitoring. To reduce storage size, partial data is stored in the onchain blocks instead of entire data. The EUâs based Fixed and variable size resource allocation techniques are proposed.
Zequan Zhou, Xiling Luo, Yi Bai, Xiaochao Wang ¡ 7 authors
Ensuring the integrity of remote data is the prerequisite for implementing cloudâedge computing. Traditional data integrity verification schemes make users spend a lot of time regularly checking their data, which is not suitable for largeâscale IoT (Internet of Things) data. On the other hand, the introduction of a thirdâparty auditor (TPA) may bring about greater privacy and security issues. We use blockchain to address the problem of TPA. However, implementing dynamic integrity verification with blockchain is a bigger challenge due to the low throughput and poor scalability of blockchain. More importantly, whether there is a security problem with blockchainâbased integrity verification is not yet known. In this paper, we propose a scalable blockchainâbased integrity verification scheme that implements fully dynamic operations and blockless verification. The scheme builds scalable homomorphic verification tags based on ZSS (ZhangâSafaviâSusilo) short signatures. We exploit smart contract technology to replace TPA for integrity verification tasks, which not only eliminates the risk of privacy leakage but also resists collusion attacks. Furthermore, we formally define a blockchainâbased security model and prove that our scheme is secure under the security assumption of cryptographic primitives. Finally, the mathematical analysis of our scheme shows that both the communication complexity and the communication complexity of an audit are O(c), in which c is the number of challenge blocks. We compare our scheme with other schemes, and the results show that our scheme has the lowest time consumption to complete an audit.
Nowadays, due to the evolution of information technologies and their adoption in the healthcare domain, new risks to medical data protection and patient privacy are increasingly present. It is therefore important to implement approaches that can prevent rapidly emerging cyber-attacks. Essentially, the adoption of cyber security measures in healthcare should be oriented towards a better assurance of patient rights and consent management. Blockchain is one of the most advanced technologies that can deal with many types of cyber threats ensuring the integrity, availability, and privacy of the data. It adds elements of trust and traceability to the data exchange processes deployed within Hospital information systems and beyond. In this paper, we study the usability of blockchain in the healthcare domain and we develop a data exchange approach based on the Hyperledger Blockchain model. The focus here will be mainly on privacy concerns and the integration of patient consent in the data sharing operational controls.
Blockchain is current demanding technology in the field of data and information security. In this paper, we present a model of the data integrity assurance by the use of blockchain. Our proposed method, the message authentication code is stored under the block of blockchain with hash value, timestamp, and nonce. The existing message authentication code, SHA-256 is used to generate the hash value to store into the blockchain after encrypting by asymmetric key cryptography with recipient public key. We also compared the strength of our blockchain based data integrity assurance method with others existing method of integrity assurance and management. We have applied penetration testing by using five different tools to test the strength and robustness of proposed method of integrity assurance. It is found that blockchain based integrity assurance method is more robust than other methods of integrity assurance.
The recently proposed Blockchain-based healthcare system proposes an interesting vision for the level of data integrity and security. This research aims to propose a conceptual model of a break-glass conceptual for Blockchain-based healthcare systems. In case of emergency, it provides access to the whole patientâs medical records for healthcare professionals as quickly as possible regarding patientsâ privacy and data security. The proposed conceptual model was designed based on blockchain technology, IPFS (InterPlanetary File System), and ABAC (Attribute-Based Access control) as a novel design in this domain. In current healthcare systems, regulatory and non-integrated offline data sources make it near impossible for timely access to patientsâ EHRs and EMRs, even in case of emergencies for healthcare professionals. Our conceptual model could be a satisfactory alternative not only for patients but also for governing organizations to handle this situation clearly by regarding patientsâ privacy. Additionally, it can work in an untrusted environment, and it doesnât require bypassing the access control system to make the patientsâ data available. In case of emergencies, healthcare professionals receive medical records access near just in time with regard to all the rights of security and privacy based on the attribute which were set by the patients in the past. This novel conceptual model has been designed by coupling Blockchain technology with IPFS, and the attribute base control system (ABAC).
Patients go to multiple healthcare providers for treatment, and their health data is generally distributed among providers. The distributed health data and the decentralized health care system structure make it ideal for blockchain-based health information systems. The authors consider the referral use case; for instance, a patient goes to his primary health Centre (PHC) for treatment and is referred to a hospital. Authentication is usually done using certificates or key cryptography, which could become cumbersome when multiple parties are involved in a healthcare interaction. The security requirements were defined, and a novel multi-party, mutual patient identity authentication scheme called “Distributed Dynamic Mutual Identity Authentication (DDMIA)” was proposed for the referral use case in a blockchain-based e-health network. The DDMIA enables the PHC to authenticate the patient to the referred hospital. The DDMIA scheme was designed using Elliptic Curve Cryptography. It was proven to be secure by assuming the hardness of the elliptic curve discrete log problem (ECDLP) and Elliptic curve computational Diffie–Hellman problem (ECDH) using CK-Model. The formal security analysis using BAN logic proved that the sessions are secure after authentication. The DDMIA scheme was simulated in the AVISPA tool and proven safe against all active attacks. DDMIA scheme was simulated in the AVISPA tool and proven safe against all active attacks. The scheme allows a patient to be authenticated by multiple parties without registering with all parties. It eliminates the need for multiple registration centers as well as digital certificates. Hence, the DDMIA scheme can be implemented for similar multiparty authentication requirements in blockchain-based networks.
The main aim of the paper is to contribute to the discussion of cryptocurrency pricing through asset pricing models. The paper develops multifactor models for the cryptocurrency valuation and discusses the elements of these models based on the literature review of scholarly articles, books, and scientific databases. We further developed the models from unit factor to five factors in order to observe whether the development is achieved by adding new factors into the model. Consequently, we pointed out the most influential factor that determines the value of cryptocurrencies.
Zhonghao Yuan, Jiaojiao Wu, Jianpeng Gong, Yao Liu ¡ 6 authors
Data owners outsource their data to remote storage providers without keeping local replicas to save their precious storage resources. However, the ownership and management of data are separated after outsourcing. How to ensure the integrity and recoverability of outsourced data becomes a significant problem. Provable Data Possession (PDP) and Proofs of Retrievability (POR) are two cryptographic protocols that enable users to verify the integrity of outsourced data. Nevertheless, the stateâofâtheâart PDP and POR schemes either need users to perform the complicated audit tasks by themselves or delegate these tasks to a ThirdâParty Auditor (TPA). Moreover, these schemes are constructed on a centralized storage framework which vulnerably suffers singleâpointâofâfailure. In this paper, we propose a blockchainâbased decentralized selfâauditing scheme with batch verification. Firstly, data owners outsource their data to decentralized storage nodes, which can achieve selfâauditing based on blockchain without TPA. Secondly, our scheme uses Pedersenâbased polynomial commitment to significantly reduce the number of authenticators. Furthermore, we propose a batch verification algorithm, which can verify multiple proofs from different storage nodes to improve the verification efficiency. Finally, we analyze the security of our scheme and implement a gasâefficient system prototype using the smart contracts of the Ethereum Reposten test network. The results demonstrate that the scheme is practical.
The cloud storage service provides the storage and access function for massive data, reducing the management cost for large amounts of data. The data integrity verification scheme in cloud storage can be employed to help users confirm the integrity of outsourced data. Although public data integrity verification schemes allow users to outsource data integrity verification to third-party auditor (TPA), there are still many problems with centralized TPA in terms of security and efficiency. In recent years, researchers have tried to apply blockchain technology to solve the centralization problem of traditional methods, but these schemes do not pay attention to the problem of efficiency degradation caused by the use of blockchain technology. This paper proposes an efficient data integrity verification scheme for multi-cloud storage services by using blockchain technology. The overall verification can verify the integrity of multiple CSPs, which solves the problems of low computational efficiency. Local verification can trace the source to the specific damaged CSP, which is more secure and reliable. In addition, this paper puts the data verification process directly in the blockchain for public execution and provides data integrity verification services without the assistance of any third-party audit platform, avoiding the security problems caused by untrusted TPA. Theoretical analysis and experiments verify the safety and effectiveness of the scheme.
In recent years, blockchain technology has been applied in the educational domain because of its salient advantages, i.e., transparency, decentralization, and immutability. Available systems typically use public blockchain networks such as Ethereum and Bitcoin to store learning results. However, the cost of writing data on these networks is significant, making educational institutions limit data sent to the target network, typically containing only hash codes of the issued certificates. In this paper, we present a system based on a private blockchain network for lifelong learning data authentication and management named B4E (Blockchain For Education). B4E stores not only certificates but also learnersâ training data such as transcripts and educational programs in order to create a complete record of the lifelong education of each user and verify certificates that they have obtained. As a result, B4E can address two types of fake certificates, i.e., certificates printed by unlawful organizations and certificates issued by educational institutions for learners who have not met the training requirements. In addition, B4E is designed to allow all participants to easily deploy software packages to manage, share, and check stored information without depending on a single point of access. As such, the system enhances the transparency and reliability of the stored data. Our experiments show that B4E meets expectations for deployment in reality.
With the growing maturity of blockchain technology, its peer-to-peer model and fully duplicated data storage pattern enable blockchain to act as a distributed ledger in untrustworthy environments. Blockchain storage has also become a research hotspot in industry, finance, and academia due to its security, and its unique data storage management model is gradually becoming a key technology to play its value in various fieldsâ applications. However, with the increasing amount of data written into the blockchain, the blockchain system faces many problems in its actual implementation of the application, such as high storage space occupation, low data flexibility and availability, low retrieval efficiency, poor scalability, etc. To improve the above problems, this paper combines off-chain storage technology and de-duplication technology to optimize the blockchain storage model. Firstly, this paper adopts the double-chain model to reduce the data storage of the major chain system, which stores a small amount of primary data and supervises the vice chain through an Application Programming Interface (API). The vice chain stores a large number of copies of data as well as non-transactional data. Our model divides the vice chain storage system into two layers, including a storage layer and a processing layer. In the processing layer, deduplication technology is applied to reduce the redundancy of vice chain data. Our double-chain storage model with high scalability enhances data flexibility, is more suitable as a distributed storage system, and performs well in data retrieval.
In recent years, the spread of information and communication technology has led to the emergence of e-government, which is the electronic replacement of government services. E-government is said to be compatible with blockchain technology, which has led to various studies on the possibility. Notarization, one of the functions of the government, has particularly been examined for the potential adoption of blockchain technology. However, because the notary public must authenticate the document’s contents during the notarization process, they have been difficult to replace with smart contracts. In this study, we focus only on fixed date notarizations and propose a fully automated notarization system by combining a national eID card with Public Key Infrastructure and smart contracts. A fixed date is a notarization that allows a notary public to guarantee that a document existed, regardless of the authenticity of the document’s content. Therefore, it can be replaced by a smart contract. Specifically, our proposed system automatically authenticates the creator and the document for electronic documents signed with a national eID card and uses the transaction receipt generated when the information is stored on the blockchain as a certificate of notarization. Verification of the signed data is done inside the blockchain by smart contracts, which eliminates the need for a verification authority. We further demonstrate the effectiveness of the proposed method in a Japanese use case as proof of concept.
Hanan E. Alhazmi, Fathy Eassa, Suhelah M. Sandokji
The world is facing a growth in the amount and variety of data generated by both users and machines. Despite the exponential increases, the tools and technologies developed to manage these data volumes are not intended to meet security and data protection requirements. Additionally, most of the current big data security systems are offered by a centralized third party, which is vulnerable to many security threats. Blockchain technology plays a significant role by addressing modern technology concerns such as decentralization, non-tampering, trust, data ownership, and traceability, making it great potential to protect personal information. This research presents a new big data security solution empowered by blockchain technology and incorporates fragmentation, encryption, and access control techniques. Our proposed fragmentation algorithm takes into account the data ownerâs demand for encryption to be added to the fragmentation process. Furthermore, data fragments will be stored in the distributed manner offered by the big data environment, resulting in an additional layer of data protection. In order to achieve an optimal security solution, we aim to enhance big data security with acceptable overhead and avoid the encryption overhead for non-sensitive and low-sensitive data portions. We present the results of our implemented techniques to highlight that the overheads (in terms of computation time) introduced by our solution are negligible relative to its security and privacy gains.
A. Ross Taylor, Austin Kugler, Praneeth Babu Marella, Gaby G. Dagher
Achieving interoperability between healthcare providers is a major challenge. Current systems for managing prescription records suffer from data siloing, unnecessary record duplication, and slow record transfers. In many systems, patients do not retain control over their prescription data. Instead, they must use an intermediary to access or transfer their records. Furthermore, record transfers suffer from differing standards between providers, outdated communication methods, and information blocking. Solving these problems necessitates the creation of an interoperable prescription management system. Realizing such a system requires considering security, efficiency, scalability, and other challenges. Recent regulatory actions attempt to address these challenges, but fundamental issues persist. This paper proposes a patient-centric and interoperable prescription system that ensures patient control, prevents information blocking, and improves transfer efficiency. We call our solution VigilRxâa system that uses blockchain and smart contracts to manage prescriptions. Stakeholders exist as one of three role-based smart contracts within the system: patient, prescriber, or pharmacy. These role contracts ensure the system is patient-centric by assigning ownership of prescription records directly to patients. Our smart contracts also ensure the systemâs interoperability, as we use a standardized prescription contract to ensure records can be easily managed. VigilRxâs use of blockchain also promotes transparency by providing patients an explicit list of parties that hold permission to access their records. Use of existing software patterns allows the system to adapt as needed. We implement VigilRx and show that it is both scalable and efficient.
Secure management of Critical National Infrastructures (CNI) is a burning challenge to any state. As a CNI, Electronic Healthcare System (EHS) infrastructure records citizens’ medical records, raising security and privacy concerns. Traditional EHS functions independently where patients’ records are recorded and maintained in centralized systems that produce massive redundant data. Due to the non-coherence of these systems, data atomicity is not maintained; hence research results based on these data create questioning. Moreover, medical records are valuable for research but cannot be public due to security and privacy. Blockchain (BC) is currently considered a potential solution for the challenges. Blockchain can integrate every independent EHS as a bridging platform. The solution can ensure data uniqueness and overcome security issues. The prime difficulties for the integration are data synchronization of the traditional EHS and BC-based EHS. Furthermore, the autonomous interoperability betweenSQLandNoSQLdatabase used in typical EHS and BC-based EHS, respectively, is a prime challenge. Therefore, this research proposes a Blockchain-based framework that bridges Traditional E-Health Systems(TEHS) and allows uninterruptible data exchanges between two systems, even for archive medical records. Beyond that, the framework shows an elevated way to overcome a single point of failure, data security, access control, etc., issues in a centralized system. Finally, the testbed implementation justifies the proposed architecture.
Open banking allows banks and financial sectors to easily access the customersâ financial data which is revolutionizing. It also provides the customers with excellent cloud access to various providersâ wide range of financial services. The storage of such sensitive services and data on cloud servers is a doubleâedged sword. It can ease and support fineâgrained access to such services/data anywhere and anytime, supporting the open banking system. But, on the other hand, data privacy and secrecy are a challenge. Thus, efficient access control should exist for open bankingâs services and data to protect cloudâhosted financial sensitive data from unauthorized customers. This paper proposes a new access control scheme that employs blockchain for the keyârevocation process. We implement the smart contractâs functions on the Ethereum platform and test the contractâs code on the Kovan Testnet before deploying it to the Mainnet. Although the customer is authenticated to open banking, his key/s can be revoked according to the status response of the bank branch. Thus, his access to financial services and data is denied. We did comprehensive experiments for the revocation status response time, data exchanged until receiving the revocation status, and the time spent updating the policy. Also, we compared the results of our proposed scheme with two wellâknown methodsâCertificate Revocation List (CRL) and Online Certificate Status Protocol (OCSP). The experimental results show that our proposed scheme (BKRâAC) has a faster response time than Certificate Revocation List (CRL) and Online Certificate Status Protocol (OCSP) in case of nonrevoked keys/certificates and a slower response time in case of revoked keys to avoid nonrevoking a revoked key. But the data exchanged is an average for BKRâAC between CRL and OCSP, which is still a tiny amount and accepted. The security analysis proved that our scheme is secure against some wellâknown attacks on open banking systems. In addition, it is also secured against the chosenâtext attack by employing the challengeâresponse authentication mechanism.
The Know Your Client (KYC) process is an essential part of the financial ecosystem. The KYC process requires banks to validate and verify primary documents. The market these days, though, is flooded with KYC utilities that facilitate this process and share these documents with multiple entities, however they provide very little value addition. Blockchain technology, with its concept of immutable timestamped ledgers and distributed systems, can effectively facilitate banks to improve their KYC methods by allowing near real-time data exchange among various entities for quicker and effective validation ensuring data integrity alongside bringing down the time and costs significantly.
The distribution of information through web protocols is today based on the client-server model. Recently, decentralized protocols with greater availability appear as well as blockchain-based attestation methods, allowing for proving the existence of information. In combination, these methods promise a secure, decentralized and long-term storage. However, there exist two major problems: (1) the scalability of blockchains limits their storage capacity and (2) various (de)centralized web protocols are in use and could alleviate this problem, but they do not support blockchain-based attestations. In this paper, we extend an approach for blockchain-based attestation with compatibility for multi-protocol storage. Instead of specific protocols or blockchains, the extended approach aims to contribute novel concepts to the discussion on blockchain scalability. It augments the capabilities of existing protocols for applications such as certification or timestamping of digital artifacts. With the use of decentralized protocols such as IPFS, further availability and inherent resilience properties are gained, allowing for applications such as open research repositories and digital registries. We discuss the architecture of the extended approach, a possible implementation in a smart contract on the Ethereum blockchain with IPFS and Git, and evaluate the time and cost of attestations.