Cryptographic accumulators are a common solution to proving information about a large set S. They allow one to compute a short digest of S and short certificates of some of its basic properties, notably membership of an element. Accumulators also allow one to track set updates: a new accumulator is obtained by inserting/deleting a given element. In this work we consider the problem of generating membership and update proofs for \em batches of elements so that we can succinctly prove additional properties of the elements (i.e., proofs are of constant size regardless of the batch size), and we can preserve privacy. Solving this problem would allow obtaining blockchain systems with improved privacy and scalability.
Web3 represents an evolution of the centralized and siloed topology of Web2 by focusing on more connected, decentralized, and open technology to democratize data and services between databases, tools, devices, people, teams and organizations to provide secure single sources of truth on decentralized trust lay-ers. However, sensitive data, such as intellectual property, classified information, personal data, or medical records, cannot be distributed to those without explicit access. A standard solution is to encrypt the data before uploading and then distribute the decryption key to select persons. This solution does not sufficiently protect against data leakage. In addition, legal, contractual, and GDPR requirements are not met in current Web3 systems. This study suggests critical requirements for any Web3 system that targets sensitive data, private and permissioned needs, and enterprise and governmental applications. A preliminary framework is then introduced for building compliant Web3 systems to the suggested requirements. The study proposes changes to the Inter Planetary File System (IPFS) protocol, with the main change being that each request checks against a ledger if the requestor has access to the data. Two novel Ethereum smart contracts, Enterprise Architecture and Smart Legal Contract, are presented to meet the suggested requirements.
A medical record is an important part of a patient’s follow-up. It comprises healthcare professionals’ views, prescriptions, analyses, and all information about the patient. Several players, including the patient, the doctor, and the pharmacist, are involved in the process of sharing, and managing this file. Any authorized individual can access the electronic medical record (EMR) from anywhere, and the data are shared among various health service providers. Sharing the EMR requires various conditions, such as security and confidentiality. However, existing medical systems may be exposed to system failure and malicious intrusions, making it difficult to deliver dependable services. Additionally, the features of these systems represent a challenge for centralized access control methods. This paper presents SEMRAchain a system based on Access control (Role-Based Access Control (RBAC), Attribute-Based Access Control (ABAC)) and a smart contract approach. This fusion enables decentralized, fine-grained, and dynamic access control management for EMR management. Together, blockchain technology as a secure distributed ledger and access control provides such a solution, providing system stakeholders with not just visibility but also trustworthiness, credibility, and immutability.
Most blockchains are designed to be immutable such that an object, e.g., a block or a transaction, is persisted once it has been registered. However, blockchain immutability hinders blockchain development due to the increasing abuse of blockchain storage and legal obligations. To break immutability in a controlled way, Derler et al. (NDSS’19) proposed a redactable blockchain with fine-grained controllable rewriting by introducing the notion of policy-based chameleon hash (PCH). Given a PCH-based object associated with an access policy, a trapdoor holder whose rewriting privileges satisfy the access policy can alter the object. Although this work offers an elegant approach to blockchain rewriting, it lacks accountability. In practice, the trapdoor holders may abuse their rewriting privileges, and even use their chameleon trapdoor to build a device in a blackbox manner to gain illegal profits while avoiding being caught. In this paper, we introduce a new design of PCH with blackbox accountability (PCHA). Blackbox accountability offers not only linkability between any modified object and its modifier, but also traceability that enables a central authority to identify responsible trapdoor holders whose secret keys have contributed to the blackbox device. Besides modeling PCHAs, we present a generic construction of PCHAs with rigorous security proofs. We instantiate a concrete construction of PCHA by introducing a practical attribute-based traitor tracing (ABTT) with adaptive security on prime-order pairing groups. The experimental analysis demonstrates that our PCHA and ABTT schemes have modest overheads and superior functionality to the state-of-the-art solutions. In particular, the price of accountability in key generation, hash, and adaption is almost negligible compared to the state-of-the-art solution.
Ge Wang, Juanjuan Li, Xiao Wang, Junqing Li · 6 authors
Crypto management is proposed to tackle the management decision-making challenges under data asymmetry and trust asymmetry that cannot be solved merely by technical means. It emphasizes the novel management model for the real-time generation of reliable, trustworthy, and usable management decisions based on blockchain and blockchain-driven technologies. First, the framework model of crypto management with detailed descriptions of each technique is introduced, where blockchain is the underlying technology, decentralized autonomous organization (DAO) is the management structure, federated data is the decision basis, smart contract is the decision method, and non-fungible token (NFT) is the main decision incentive. Then, its collaboration mechanisms of on-blockchain DAO and off-blockchain organization as well as intra-organization and extra-organization nodes are discussed. Moreover, the potential applications of crypto management are addressed, and a case of task-oriented performance management is given to state how crypto management works to generate the real-time management decisions. Toward the end, the future research directions are pointed out in this emerging new area.
Jin Wang, Wei Ou, Osama Alfarraj, Amr Tolba · 6 authors
Since transactions in blockchain are based on public ledger verification, this raises security concerns about privacy protection. And it will cause the accumulation of data on the chain and resulting in the low efficiency of block verification, when the whole transaction on the chain is verified. In order to improve the efficiency and privacy protection of block data verification, this paper proposes an efficient block verification mechanism with privacy protection based on zero-knowledge proof (ZKP), which not only protects the privacy of users but also improves the speed of data block verification. There is no need to put the whole transaction on the chain when verifying block data. It just needs to generate the ZKP and root hash with the transaction information, then save them to the smart contract for verification. Moreover, the ZKP verification in smart contract is carried out to realize the privacy protection of the transaction and efficient verification of the block. When the data is validated, the buffer accepts the complete transaction, updates the transaction status in the cloud database, and packages up the chain. So, the ZKP strengthens the privacy protection ability of blockchain, and the smart contracts save the time cost of block verification.
Since its conceptualization, blockchain technology has witnessed continuous and rapid development, bringing profound changes to computer science, law, and economics. In 2008, the initial blockchain system was merely a growing list of records linked together using cryptography. Today, however, blockchains have become the foundation of most digital currencies, robust cloud computing platforms, and dependable databases for tracking supply chain information. Despite challenges and controversies, blockchain technology has the potential to help build a trustworthy and efficient digital world.
Diana Vanessa S. Castillo, Chelsee Nicole B. Co, Katrine Grace R. Maranan, Daren Jay Quinio · 5 authors
Academic records are necessary requirements for employment and further studies. Despite being critical infor-mation that assesses one's eligibility in different disciplines, credentials are oftentimes difficult to acquire and inefficient to handle. Effectively, these manual and centralized processes make academic records vulnerable to fraudulent activities such as tampering and falsification. This project designed an academic record management and verification system using blockchain technology which offers enhanced security, immutability, trans-parency, and process improvement. Unlike previous works that used Bitcoin, Ethereum, or Hyperledger as their blockchain network, this project implemented its decentralized application (dApp) in the Solana network due to its faster processing speed, low-cost transaction fees, and expanding ecosystem. The dApp covers the generation, issuance, and verification of the most commonly requested credentials-the Transcript of Records (TORs) and diplomas. The intended users of this application are the universities, students, and third party entities that need to verify academic credentials for employment or other reasons. It was identified that the blockchain-based system provides a better means to (1) preserve the integrity of academic records, (2) transact between record handlers and requestors and (3) execute the processes of record generation and verification.
Moyixi Lei, Shuangyin Liu, Na Luo, Xinting Yang · 5 authors
Traceability systems have changed the way food safety is managed and data is stored. Blockchain tracking services now provide customers with an infrastructure that allows them to easily access data online. However, there are limitations to these new capabilities, such as a lack of transparency and the existence of privacy and security challenges. Additionally, as the need for more agile, private, and traceability secure data solutions continues to grow exponentially, rethinking the current structure of blockchain agricultural traceability is mission-critical for a country. By leveraging and building upon blockchain's unique attributes, including tamper-evident, security hash crypto-data, and distributed ledger, we have proposed a prototype that allows traceability data to be reliably stored via blockchain while simultaneously being secured, with completeness auditing to enhance credibility. The result, the trusted auditing chain (TA chain), is a flexible solution that assures data security and solves challenges such as scalability and privacy-preserving. The TA chain works through Schnorr-style non-interactive Zero-knowledge proof to support security automatical choose privacy augmented. In addition, The TA chain can audit more than 1000 transactions within 1ms, and its error stabilizes below the 250 μs, which proves a security and fair traceability system to assure that data is distributed and reliably, and provably audited.
Hang Thanh Bui, Omar Khadeer Hussain, Morteza Saberi, Farookh Hussain
Blockchain is being used in the supply chain from a local to a global scale with its ever-increasing maturity and ubiquity. However, in the presence of information flow from a subjective source with no digital footprint, such as a claim, or a promise, there is a gap in the application of the Blockchain framework in supply chain risk management perspective. The existing mechanisms such as Proof of Work (PoW), Proof of Authority (PoA) or Proof of Stake (PoS) do not verify and validate subjective information presented in Service level agreement (SLA). We address this open issue in this paper by proposing the Proof by Earnestness (PoE) consensus mechanism that aims to validate the authenticity and legitimacy of such information. Subjective Information Authenticity Earnestness Framework (SIAEF) seeks to be a decentralised application to enable the trustworthiness of subjective information to become accountable.
As decentralized finance (DeFi) applications take off and pose to revolutionize the world's financial infrastructure, the current public blockchains fall short in financial privacy. That is a significant barrier for traditional financial institutions to enter DeFi. The Oasis Ethereum ParaTime proposes a new privacy-first blockchain network to execute Ethereum smart contracts and trade Ethereum digital assets. It provides full transparency into smart contract code and logic. The smart contract is executed on replicated virtual machines on a decentralized set of validator nodes, and the result is guaranteed to be correct through the consensus of those nodes. Yet, the contract data and state are confidential even to the validators and node operators. The transactions and results are only revealed to users who submit the transactions. In this article, we will explore the design of the Oasis Ethereum ParaTime, and its potential applications. We will also discuss an early testnet we launched on the Oasis Network and its future plans.
This research paper puts emphasis on using cloud computing with Blockchain (BC) to improve the security and privacy in a cloud. The security of data is not guaranteed as there is always a risk of leakage of users’ data. Blockchain can be used in a multi-tenant cloud environment (MTCE) to improve the security of data, as it is a decentralized approach. Data is saved in unaltered form. Also, Blockchain is not owned by a single organization. The encryption process can be done using a Homomorphic encryption (HE) algorithm along with hashing technique, hereby allowing computations on encrypted data without the need for decryption. This research paper is composed of four objectives: Analysis of cloud security using Blockchain technology; Exceptional scenario of Blockchain architecture in an enterprise-level MTCE; Implementation of cipher-text policy attribute-based encryption (CP-ABE) algorithm; Implementation of Merkle tree using Ethereum (MTuE) in a Multi-tenant system. Out of these four objectives, the main focus is on the implementation of CP-ABE algorithm. CP-ABE parameters are proposed for different levels of tenants. The levels include inner tenant, outer tenant, Inner-Outer-Tenant, Inner-Outer-External-Tenant, Outer-Inner-Tenant, External-Outer-Inner-Tenant and the parameters such as token, private key, public key, access tree, message, attribute set, node-level, cipher-text, salting which will help in providing better security using CP-ABE algorithm in a multi-tenant environment (MTE) where tenants can be provided with different levels of security and achieved 92 percentage of authenticity and access-control of the data.
Priyanka Pandit, Daniel Nevius, Vibhav Srivaths, Mihai Diaconeasa
Abstract The Nuclear Power Plant (NPP) project lifecycle consists of multiple organizations, private and public, that work together to carry out the licensing and regulation, commissioning, construction, supply chain management, decommissioning, and non-proliferation of nuclear power plants. Each stage of the lifecycle generates a considerable amount of documentation that needs to be archived and made available on request. In this paper, we examined the current frameworks employed by the stakeholders of nuclear power plant lifecycles for data generation, classification, archival, and exchange and we evaluated the use of distributed ledger technology for data management. We further demonstrated the implementation of distributed ledger technology to capturing and immutable recording nuclear supply chain structure, production, and failure data. Distributed Ledger Technology (DLT) promises to address the current bottlenecks in the lifecycle management of nuclear power plants with faster data exchange times, lower processing cost of documents, bridging the gap between perceived and actual risk, faster decisions, customizable transparency in job tasks being executed, improved cash flow, instant validation of job completion, reduction in logistical friction, and sped up supply chain decisions for clients. We gave a comprehensive review of distributed ledger technology, its properties and an open-source permissioned distributed ledger system called Hyperledger Fabric. Each sector of the nuclear power plant lifecycle was analyzed for data management bottlenecks and building on our discussion of employing distributed ledger technology we discussed the pathway in which Hyperledger Fabric can be employed to address the data management bottlenecks in each stage of the lifecycle including, licensing and regulation, commissioning, construction, supply chain management, decommissioning, and non-proliferation.
The thesis addresses the problem of scalability in decentralized blockchains in the context of the trade-off between transaction throughput and hardware requirements to participate in the network. Rollups are presented, that is technologies to verify on-chain blocks executed off-chain by minimizing the assumptions of trust. The variant of the Optimistic Rollups, in particular of Optimism and the use of invalidity proofs through interactive binary search and of the Validity Rollups, in particular of StarkNet, and the use of validity proofs through STARKs are discussed. Finally, the two solutions are compared on withdrawal time, on the cost of transactions and techniques to minimize it, on the possibility of applying the technology recursively, on compatibility with Ethereum and on the licenses used.
Abdelhadi Rachad, Khalid Bouragba, Mohammed Ouzzif
The traditional cloud Service-Level Agreement (C-SLA) ensures that cloud providers meet certain business-level requirements and provide customers with a set of clearly defined services as clauses in a simple IT contract. These agreed terms create a foundation of trust on which a customer agrees to use the services of a cloud provider. They also reflect the provider's commitments to Quality of Service (QoS) and cloud infrastructure. Suppliers must also have KPIs that they can measure the reality is essential to have a dashboard and monitoring for the governance of these agreements such contracts require dedicated administration teams with financial, operational and time-consuming compliance. Our objective in this paper is to propose a new service-oriented smart contract model of smart cloud SALs to cloud providers is a microservices approach that also allows to create several independent services that then interact in a secure and very useful way. During the execution of these microservices, all the validation steps are recorded in the blockchain, which makes it possible to secure and control the effectiveness of their actions using predefined performance indicators.
Ertem Nusret Tas, John R. Adler, Mustafa Al-Bassam, Ismail Khoffi · 6 authors
Accountability, the ability to provably identify protocol violators, gained prominence as the main economic argument for the security of proof-of-stake (PoS) protocols. Rollups, the most popular scaling solution for blockchains, typically use PoS protocols as their parent chain. We define accountability for rollups, and present an attack that shows the absence of accountability on existing designs. We provide an accountable rollup design and prove its security, both for the traditional `enshrined' rollups and for sovereign rollups, an emergent alternative built on lazy blockchains, tasked only with ordering and availability of the rollup data.
Metaverse has rekindled human beings' desire to further break space-time barriers by fusing the virtual and real worlds. However, security and privacy threats hinder us from building a utopia. A metaverse embraces various techniques, while at the same time inheriting their pitfalls and thus exposing large attack surfaces. Blockchain, proposed in 2008, was regarded as a key building block of metaverses. it enables transparent and trusted computing environments using tamper-resistant decentralized ledgers. Currently, blockchain supports Decentralized Finance (DeFi) and Non-fungible Tokens (NFT) for metaverses. However, the power of a blockchain has not been sufficiently exploited. In this article, we propose a novel trustless architecture of blockchain-enabled metaverse, aiming to provide efficient resource integration and allocation by consolidating hardware and software components. To realize our design objectives, we provide an On-Demand Trusted Computing Environment (OTCE) technique based on local trust evaluation. Specifically, the architecture adopts a hypergraph to represent a metaverse, in which each hyperedge links a group of users with certain relationship. Then the trust level of each user group can be evaluated based on graph analytics techniques. Based on the trust value, each group can determine its security plan on demand, free from interference by irrelevant nodes. Besides, OTCEs enable large-scale and flexible application environments (sandboxes) while preserving a strong security guarantee.
Medical records management had always been a challenging in healthcare sector. Traditionally, medical records are handled either manually or electronically that are under the stewardship of hospitals/healthcare institutions. A patient centric approach is the new paradigm where patient is an inherent part of the healthcare ecosystem controlling the access and sharing of his/her personal medical care information. Medical care information requires robust security and privacy. Also there are other issues like confidentiality, interoperability, scalability, cost efficiency and timeliness that need to be addressed. To achieve these objectives, this paper proposes a novel-scalable patient centric yet privacy preserving framework for efficient and secure electronic medical records management. In addition, proposed system generates a unified trusted record and authentication role mapping for enforcing secure access control for medical records using complex encryption algorithms. This paper identifies 13 key performance factors for performance comparison of proposed framework with traditional models. Ethereum and Binance Smart Chain acted as a benchmark platform for performance evaluation of MRBSChain on the basis of three metrics (transaction cost, average block time and deployment cost).At last, a comparative analysis of MRBSChain with other state of art blockchain systems on the basis of execution time is presented in the paper.
Summary In today's world, data management plays a key role in smart healthcare applications. However, data availability, trustworthiness, confidentiality, and security are the major issues faced by current healthcare data management systems. The modern healthcare systems manage Electronic Medical Records (EMR) using a centralized manner, which increases the single point of failure in the event of a natural catastrophe. In this paper, a new robust Blockchain‐based Medical Cloud (BC‐MedCl) framework has been proposed to provide secure EMR sharing between patient and doctor. Primarily, Internet of Things (IoT) devices will gather the health‐related data of the patient periodically. The proposed framework then stores the encrypted EMRs in cloud storage while their correlating hash values are placed into the blockchain. Finally, a decentralized selective smart contract‐based access control mechanism is developed to enhance the security of the proposed system. The prototype file‐sharing performance of the proposed architecture has been evaluated using the Ethereum platform. The performance results manifest that the proposed blockchain framework is more effective to handle EMR in the real‐time healthcare system with a superior accuracy ratio of 98.7% and a lesser latency ratio of 25% as compared with the existing systems.