The application of virtual power plants makes up for the shortcomings of new energy sources and provides ideas for the development of low-carbon power systems. As the whole society attaches importance to information security issues, user information security issues based on blockchain trading platforms have brought challenges to the development of virtual power plants. This paper proposes a virtual power plant user identity verification method based on improved zero-knowledge proof. In order to solve the problem of increased node users and increased resource consumption for identity verification, the article proposes a distributed parallel verification strategy. The test results show that the method meets the field requirements in terms of accuracy and recall of identity verification. And compared with other verification methods, it has certain performance advantages.
Supply chain applications operate in a multi-stakeholder setting, demanding trust, provenance, and transparency. Blockchain technology provides mechanisms to establish a decentralized infrastructure involving multiple stakeholders. Such mechanisms make the blockchain technology ideal for multi-stakeholder supply chain applications. This chapter introduces the characteristics and requirements of the supply chain and explains how blockchain technology can meet the demands of supply chain applications. In particular, this chapter discusses how data and trust management can be established using blockchain technology. The importance of scalability and interoperability in a blockchain-based supply chain is highlighted to help the stakeholders make an informed decision. The chapter concludes by underscoring the design challenges and open opportunities in the blockchain-based supply chain domain.
Eugenio Balistri, Francesco Casellato, Carlo Giannelli, Cesare Stefanelli
To identify health risks in working environments, it is crucial for companies to share personal health data demonstrating to clients and suppliers their employees are healthy, while being compliant with data protection legislation. Based on these considerations, our Blockchain-based BlockHealth solution allows personal health data sharing with tamper proofing and data protection. Traditionally, the Blockchain guarantees data immutability but not confidentiality. On the contrary, BlockHealth stores in the Blockchain only hash values of data. Health data is stored in private databases managed by companies, thus also allowing to delete data in compliance with the right to be forgotten.
Lattice-based non-interactive zero-knowledge proof has been widely used in one-way communication and can be effectively applied to resist quantum attacks. However, lattice-based non-interactive zero-knowledge proof schemes have long faced and paid more attention to some efficiency issues, such as proof size and verification time. In this paper, we propose the non-interactive zero-knowledge proof schemes from RLWE-based key exchange by making use of the Hash function and public-key encryption. We then show how to apply the proposed schemes to achieve the fixed proof size and rapid public verification. Compared with previous approaches, our schemes can realize better effectiveness in proof size and verification time. In addition, the proposed schemes are secure from completeness, soundness, and zero-knowledge.
The use of digital health records, stricter health laws and the growing need for health records exchange points towards the need for an efficient security and privacy preserving mechanism. For Health Insurance management systems, multiple entities exchange health information which is used for decision making. Since multiple authoritative entities are involved, a secure and efficient information sharing protocol is required as extremely sensitive health information is exchanged among the entities. Hence this paper aims to put forward a novel a decentralized authentication system based on Blockchain known as Insurance Claim Blockchain (ICBChain) system. The proposed system ensures privacy of patients, provides secure information exchange and authentication of entities. An implementation of the proposed system is provided using Ethereum Blockchain. The security and performance analysis of the system shows its potential to satisfy Healthcare security requirements and its efficiency respectively
Estruturas de dados tem sido um dos principais objetos de estudo da computação. Alguns cenários de aplicação dessas estruturas possuem requisitos relacionados à segurança e integridade dos dados nelas contidos. Deste modo, no decorrer da história da computação foram propostas estruturas de dados verificáveis, que apresentam características que visam atender a alguns requisitos de segurança como a garantia de imutabilidade e a verificação de um item de dado pertencente a estas estruturas. Este artigo analisa duas estruturas de dados verificáveis, a saber, a Mekle Tree e a Merkle PATRICIA Trie, descrevendo seus conceitos, características e cenários de aplicação no contexto das blockchains Ethereum e Neo.
Enrico Bacis, Dario Facchinetti, Marco Guarnieri, Marco Rosa · 6 authors
A Time-Lock enables the release of a secret at a future point in time. Many approaches implement Time-Locks as cryptographic puzzles, binding the recovery of the secret to the solution of the puzzle. Since the time required to find the puzzle’s solution may vary due to a multitude of factors, including the computational effort spent, these solutions may not suit all scenarios.
Ke Huang, Yi Mu, Fatemeh Rezaeibagha, Xiaosong Zhang
Hash function is generally known as symmetric and private for use. However, when applying under public key infrastructure, it immediately yields a notion called chameleon hash function. Based on the chameleon hash, this chapter generalizes and formalizes the notion of public key hash (PKH) scheme by rigorous algorithmic design and security models of indistinguishability and collision-resistance. PKH is another form of the trapdoor commitment, which serves as a basic element for zero knowledge and IND-CCA2 secure public key encryption schemes. Notably, PKH (e.g. chameleon hash) has been recently used to build the redactable blockchain where block hash and transaction are supposed to be redacted without impairing consistency. To begin with, this chapter first review background information of PKH. Then, it instantiates by various PKH schemes: ACH, HCCH, PCH, TUCH and RCH which are mostly from our related works. By rich analysis of algorithmic design and proof techniques of security reduction, this chapter gives more empirical knowledge, insightful instruction and practising sources for the readers to follow. To summarize, PHK is considered as a basic primitive for many other cryptographic schemes. It is an easy starting point for a beginner to follow but can also extend to sophisticated design. The simplicity of the instantiated cases helps the reader quickly grasp and practise proof techniques given in this chapter
The rapid growth of storage overhead on public blockchains has urged the use of light clients that only store a small fraction of blockchain data and rely on other bootstrapped full nodes for data retrievals. Unfortunately, current blockchain light client designs are far from satisfactory. First, outsourcing retrieval requests could raise severe concerns about result correctness and privacy threats. Second, current light clients do not support rich query and enforce fee payments to full nodes. Given that blockchain storage increases day by day, enabling effective rich blockchain queries and fairly compensating full nodes’ ever growing costs has become extremely necessary. In this article, we propose a general and secure paid query framework to simultaneously meet those demands above. Specifically, we leverage the integration of trusted hardware (e.g., Intel SGX) and smart contract as a starting point for building efficient yet secure query processing with fair payments. Then, we further craft several crucial performance and security refinement designs to boost query efficiency and enforce result correctness, and also explore an enclave-facilitated fair settlement mechanism for on-chain cost optimizations. We implement a prototype of our paid query framework and the experimental result has demonstrated its practically affordable cost.
Mengyuan Cheng, Guoliang Liu, Yongshun Xu, Ming Chi
Blockchain is regarded as a potential technology for transforming the architecture, engineering, and construction (AEC) industry, and the number of related publications is increasing rapidly. However, a systematic review of blockchain applications in the AEC industry is lacking. The objective of this study was to review the current status of blockchain applications via a bibliometric analysis combined with a systematic literature review. According to related articles collected from databases, the present status of blockchain was analysed with regard to the distribution of articles over publication years, journals, institutions, countries, cooperation networks between authors, keyword co-occurrence networks, and research methodologies. The results indicated that research on blockchain applications is still relatively new and fragmented with regard to several topics. Five areas of benefit were identified: (i) supply chain management, (ii) contract management, (iii) information management, (iv) stakeholder management, and (v) integration management. On the basis of the technology–organisation–environment framework, nine types of challenges were identified. Future research opportunities were proposed according to the research findings. This study contributes to the current body of knowledge and provides guidelines for further research on blockchain applications in the AEC industry.
Yangfei Lin, Jie Li, Shigetomo Kimura, Yuanyuan Yang · 6 authors
The applications of Internet of Things have emerged in every aspect of people’s life. The volume of data gathered can be enormous. Enterprises and personal consumers are increasingly reliant on cloud storage services instead of local storage. While they enjoy the convenience of cloud storage services, they also worry about the integrity of the cloud-stored data since they do not physically own the data. To enable public integrity auditing, third-party auditors as trusted ones verify data integrity on behalf of the data owner. However, the vulnerability of auditors should also be considered. We propose a consortium blockchain-based public integrity verification system (CBPIV). In CBPIV, the auditor behaviors are recorded in the consortium blockchain so that authorized parties can audit the auditor to see if the verification results are correct. A smart contract is deployed to check the behavior of the auditor automatically, which can trigger alerts for unusual behaviors. The evaluation on both security and performance shows that our proposed scheme is secure and alleviates the burden on data owners of limited computation capability.
With the rise in digitization of documents stored online, it is important to have a document verification process. It involves customized verification and authentication of a document based on the content of the document. Among all the certificates, the educational certificate is one of the most important certificates, especially for students. Unfortunately, it is very easy to fake documents that are hard to identify nowadays and are often considered original. Blockchain has recently emerged as a potential alternative to manual verification of certificates. It provides a distributed ledger that is verifiable with cryptographic mechanisms. Also, it provides a common platform for easily sharing, storing, and accessing documents. The identity of the students can be verified using government authorized identity proofs. This paper proposes the use of such unique identity number and secret phrase provided by the student to further improve the security of the certificate verification system. The student's identity and document are both verified by matching the hashes already present in the Blockchain. Also, in the proposed method the documents are linked to the student to add another layer of verification. The implementation of this proposed platform can be used to issue, receive and verify the certificates.
Eranga Bandara, Xueping Liang, Peter Foytik, Sachin Shetty
Cyber threat information (CTI) sharing involves processes of the collection, analysis and sharing of cyber threat information among multiple organizations. CTI is highly sensitive and inadvertent access can harm an organisation’s reputation. Moreover, CTI sharing may also inadvertently advertise a vulnerability that may be present in the organisation’s infrastructure. Therefore, preserving the privacy and anonymity of the CTI participants is critical. This paper proposes "Siddhi", a blockchain and Self-Sovereign Identity(SSI) enabled CTI platform that will realize traceability, anonymization and data provenance in a scalable fashion. Siddhi is equipped with SSI-enabled mobile wallet to ensure anonymous reporting of threat information and supports TAXII and STIX standards for exchanging the threat information between participants in the blockchain network.
Due to regulations and policies enacted to protect patients' privacy, electronic health records (EHRs) must be kept as sensitive information in a secure and reliable manner. Maintaining EHRs by hospitals and safely sharing them with others have proved to be challenging tasks. In this paper, we introduce a cloud-based blockchain (CBC) approach to achieving data accessibility, redundancy, and security for storing and sharing EHRs. A lightweight CBC, called lite blockchain (LBC), is designed to store EHRs' metadata and text-based information locally. Our approach allows for big data to be safely stored in CBCs, and for information to be efficiently retrieved via LBCs. To restrict and grant access of the data to authorized participants only, we present our data security mechanism along with role-based access control policies. The experimental results show that our cloud-based blockchain approach is feasible and efficient for accessing and sharing EHRs stored both locally and in clouds.
Participating in or operating a permissioned blockchain is a complex challenge and poses a significant hurdle for many organizations. This paper creates a structure for the operation of a permissioned blockchain with seven blockchain operations categories. An onboarding process of joining a blockchain exemplifies the use of the blockchain operations categories. The article illustrates the IT management structures necessary to operate a blockchain, the on-chain and off-chain interplay for a secure blockchain solution. Our results support the efficient management of permissioned blockchains. The approach is grounded in a research project that uses a scenario-driven approach to design blockchain infrastructures for supply chains. This project uses on Hyperledger Fabric as the blockchain framework.
Abstract Health records of any type should be confidential, but simultaneously they should be accessible to an authorized user. In the current conventional health care system, health records are processed in the local database. Only authorized hospital staff can have access to the patient health records kept in health centers. The flow of information in this kind of system is center-restricted. One technology that can potentially overcome this problem is Blockchain. Blockchain technology allows sharing of data in a distributed way with benefits like privacy-preserving and secure access control. To achieve secure access control and privacy of electronic healthcare data (EHD), a secure framework for distributed sharing of the health record is proposed. The use of blockchain will remove the requirement of a trusted 3 rd party for data storage. The framework uses searchable key attribute-based encryption (ABE) for achieving fine-grain access control. The simulation results indicate that our scheme is quite effective and secure.
Abstract The biggest obstacle to electronic migrations of many systems is the need to protect the details and to check the identity of users. Currently, the use of dual-factor authentication is based occasionally on a password. The problem with these approaches is that passwords are extremely insecure and authentication by two factors usually involves the sending of code via SMS or a third-party provider. The blockchain might be a solution to this problem. A 50 billion dollar currency is managed by blockchain. But authentication could be subject to the same cryptographic principles. Thus, blockchain authentication eliminates someone from maliciously modifying the ledger when they distribute a ledger to all network members. A majority of the network shall check its validity any time a block of data is attached to a chain. That guarantees the completeness of the ledger. You can then make sure to send passwords safely using public-key encryption, such as highly protected RSA encryption. The receiver could then search for an entry in the unchanged blockchain, which would result in a remarkably safe and reliable way of handling identity verification. These rules apply for the transformation into a stable, fast, reliable, and readily available service from the election process, state identifiers to dual-factor authentication.
Smart Contracts cannot get external data directly due to the closure and determinacy of blockchain itself, limiting the extensibility of blockchain applications. Oracle is proposed to serve as a data feed to offer authenticated and deterministic external data to smart contracts. However, existing centralized oracles are efficient but vulnerable to targeted attacks and suffering from a single point of failure, while existing decentralized oracles are inefficient. The paper presents a trusted blockchain oracle based on a decentralized Trusted Execution Environment (TEE) network called Tora, which embraces both efficiency and availability. The key of Tora is a hybrid consensus mechanism with the confidential available group selection based on Proof-of-Availability (PoA). We have implemented a prototype of Tora on Ethereum with Intel Software Guard eXtensions (SGX) and evaluated it with a data-fetch use case on different measurements, including gas costs, off-chain execution time, group selection results and throughput. The results show that Tora provides considerable efficiency and scalability.
Millions of students complete their education each year and go on to do higher studies or a corporate job. In this case student credentials are verified through a lengthy document verification process. This results in significant overhead as documents are transferred between institutions for verification. There is a need for an automated credential verification system which can reduce the time required for the document verification process. Blockchain Technology can be used to reduce overhead and reduce the time taken for document verification from days to mere seconds. In this work, an attempt has been made to develop a Blockchain-based verification system for academic certificates. With the advent of public Blockchain like Ethereum, DApps (Decentralized Applications) and Smart contracts, scalable and cost effective solutions can be implemented to reduce overhead and make document verification a seamless process. The proposed solution consists of a web app which will have a front-end for registering and requesting verification, along with a backend which will have two modules: An OCR module to extract details from certificates and a Blockchain module to send and verify data stored in the Blockchain.
Abstract Various distributed ledger technologies (DLTs), such as blockchain, have evolved significantly in recent years. These technologies provide a robust and effective solution for providing confidentiality, integrity, nonrepudiation, authentication, and transparency. While blockchain has many advantages, it has various limitations as well, such as complexity, low throughput, privacy, and so on. We discuss the issues that must be considered when deciding whether to use these technologies in a given case or not. We describe the operation of blockchain, application areas where blockchain is suitable, and those where it is not. We also discuss the applicability of other emerging DLTs, apart from blockchain technology, such as Hashgraph, Zcash, Nano coin, and IOTA.