The increasing adoption of electronic health records (EHRs) has necessitated secure and efficient sharing mechanisms among healthcare institutions. However, challenges related to data integrity and privacy persist. This review study explores the potential of blockchain technology to address these challenges and enhance EHR sharing security. Blockchain offers several advantages, including immutability, transparency, and decentralization, which can significantly improve data integrity and prevent unauthorized access. Consensus algorithms like Proof-of-Work (PoW) or Proof-of-Stake (PoS) ensure data accuracy and reliability. Moreover, blockchain facilitates secure and efficient data sharing by eliminating intermediaries. Smart contracts automate processes, reducing human error and improving efficiency. Additionally, blockchain provides a transparent audit trail for tracking data access and usage. While implementing blockchain in EHR sharing systems presents challenges like scalability, performance, and regulatory compliance, careful consideration of consensus algorithms, data privacy measures, and integration with existing systems is crucial. Blockchain's potential to enhance EHR sharing security and contribute to a more efficient healthcare ecosystem makes it a promising solution.
Md. Rafid Haque, Sakibul Islam Munna, Sabbir Ahmed, Md. Tariqul Islam · 6 authors
Centralized version control systems (VCS) are vital for software development but pose risks of data loss and ownership disputes. While blockchain offers a decentralized alternative, existing solutions are often hindered by high latency, compromising the real-time collaboration essential for modern workflows. This study introduces a novel hybrid architecture combining the security of the Ethereum blockchain and the InterPlanetary File System (IPFS) with two key contributions: 1) Shamir's Secret Sharing (SSS) to create a trust-minimized model for key distribution, and 2) an authoritative-first, optimistic-fallback retrieval protocol utilizing a temporary middleware to decouple the user experience from blockchain confirmation delays. We implemented a full prototype and conducted a comprehensive performance evaluation on the public Sepolia testnet. Our results demonstrate that this architecture not only provides a secure, auditable, and resilient platform for source code hosting but also achieves highly competitive user-perceived performance. Our user-perceived push time reduces submission latency by up to 49% compared to a standard git push for common repository sizes, proving that a well-designed decentralized VCS can balance the core tenets of security and decentralization with the practical need for speed and efficiency.
The security of academic credentials is increasingly at risk due to cyberattacks and credential fraud. Traditional verification systems rely on centralised databases, creating single points of failure and privacy concerns. This paper explores Zero-Knowledge Proofs (ZKPs) with blockchain to enhance educational data security. We propose an optimised ZKP protocol for education, improving lightweight infrastructure, scalability, credential revocation, and ease of use. By refining existing techniques, our approach enhances secure, privacy-preserving credential verification, creating a resilient educational data system.
This research paper delves into the analysis of attack thresholds within Proof of Stake (PoS) blockchain consensus protocols. In the PoS system, validators participate by staking a certain amount of funds, granting them the ability to propose and vote on new blocks in the network. The influence of validators in the consensus process is determined by the proportion of funds they have bonded, thus wielding voting power commensurate with their stake percentage. A critical vulnerability in PoS systems lies in the possibility of a single validator reaching the attack threshold of 1/3 stake, which grants them the capability to disrupt network consensus. This study examines the potential of a validator reaching the attack threshold through two distinct methods. Firstly, I explore the Superior Returns Attack Threshold (SRAT) method, wherein a network member aims to increase their token ownership by investing in high-risk, high-return securities. The objective is to accumulate sufficient wealth to stake and attain an attack stake. Secondly, I investigate the Random Attack Threshold (RAT) method, whereby a validator inadvertently accumulates an attack stake due to stochastic randomness. My analysis reveals that intentional efforts to obtain 1/3 stake by a validator through the SRAT method yield a nonzero probability, posing potential security challenges for pure PoS systems. However, I demonstrate that the probability of a validator acquiring 1/3 stake through stochastic randomness with constant rewards, as observed in the RAT method, is nearly zero.
Noor Ul Ain Tahir, Umer Rashid, Hassan Jalil Hadi, Naveed Ahmad · 7 authors
This study investigated the potential of blockchain technology to transform Electronic Health Record (EHR) administration, integrity, and security. EHRs store vital health information such as medical history, diagnosis, prescriptions, and imaging findings, which may be shared with healthcare professionals to improve patient care. The existing EHR systems have a centralized framework. These centralized systems have a single point of failure, data management, integrity, and security concerns. Blockchain technology provides a solution to these problems by delivering benefits such as safety, privacy, secrecy, and decentralization. This study presents a framework for adopting blockchain technology in EHR systems, providing a comprehensive, modular, and straightforward approach. Our proposed framework addresses the constraints of existing EHR systems by providing a platform for connected and interoperable EHRs. The proposed blockchain-based patient health records management framework demonstrates the potential to address the limitations of current centralized health records systems. It offers benefits such as data privacy and security, interoperability, audibility, decentralization, and automation through the use of smart contracts. The proposed framework is implemented in Ethereum. The evaluation, i.e., cost and performance results, show that this solution is reasonable and may be used on any blockchain network, whether it is permissioned or permissionless.
Identity-based threshold signature (IDTHS) allows a threshold number of signers to generate signatures to improve the deterministic wallet in the blockchain . However, the IDTHS scheme cannot determine the identity of malicious signers in case of misinformation . To solve this challenge, we propose an identity-based threshold (multi) signature with private accountability (for short AIDTHS) for privacy-preserving blockchain . From the public perspective, AIDTHS is completely private and no user knows who participated in generating the signature. At the same time, when there is a problem with the transaction, a trace entity can trace and be accountable to the signers. We formally define the syntax and security model of AIDTHS. To address the issue of identifying malicious signers, we improve upon traditional identity-based threshold signatures by incorporating zero-knowledge proofs as part of the signature and leveraging a tracer holding tracing keys to identify all signers. Additionally, to protect the privacy of signers, the signature is no longer achievable by anyone, which requires a combiner holding the keys to produce a valid signature. We give a concrete construction of AIDTHS and prove its security. Finally, we implement the AIDTHS scheme and compare it with existing schemes. The key distribution algorithm of AIDTHS takes 13.04 ms and the signature algorithm takes 34.60 μ s . The verification algorithm takes 1 s , which is one-third of the time the TAPS scheme uses.
Mobile Crowdsourcing (MCS) has become a novel paradigm for enabling data collection by worker recruitment, and the reputation plays a crucial role in achieving high-quality data. Although identity, data, and bid privacy preserving have been thoroughly investigated with the advance of blockchain technology, existing literature barely focuses on reputation privacy, which prevents malicious workers from submitting false data that could affect truth discovery for data requester. Therefore, we propose a Blockchain-Based Reputation Privacy Preserving for Quality-Aware Worker Recruitment Scheme (BRPP-QWR). First, we design a lightweight privacy preserving scheme for the whole life cycle of the worker’s reputation, which adopts sub-address retrieval technique combined with Pedersen Commitment and Compact Linkable Spontaneous Anonymous Group (CLSAG) signature to enable fast and anonymous verification of the reputation update process. Subsequently, to tackle the unknown worker recruitment problem, we propose a Reputation, Selfishness, and Quality-based Multi-Armed Bandit (RSQ-MAB) learning algorithm to select reliable and high-quality workers. Lastly, we implement a prototype system on Hyperledger Fabric to evaluate the performance of the reputation management scheme. The results indicate that the execution latency for the reputation score verification and retrieval latency can be reduced by an average of 6.30%–56.90% compared with ARMS-MCS. In addition, experimental results on both real and synthetic datasets show that the proposed RSQ-MAB algorithm achieves an increase of at least 20.05% in regard to the data requester’s total revenue and a decrease of at least 48.55% and 3.18% in regret and Multi-round Average Error (MAE), respectively, compared with other benchmark methods.
Vid Keršič, Martin Domajnko, Sašo Karakatič, Muhamed Turkanović
Z vse pogostejšo uporabo interneta in migracijo storitev iz fizičnega sveta v digitalni, postajajo vprašanja o varnosti, zasebnosti in digitalnem lastništvu osebnih podatkov vse pogostejša. Ena izmed ključnih tehnologij, ki omogoča razvoj rešitev na tem področju, so ničelno spoznavni dokazi (ang. zero-knowledge proofs, ZKP). ZKP so kriptografski protokoli, pri katerih dokazovalec dokaže pravilnost poljubne trditve preveritelju, ne da bi pri tem razkril dodatne informacije ali svoje podatke. V članku predstavimo ZKP protokole in njihove razlike, s posebnim poudarkom na dveh najpogostejših družinah protokolov: zk-SNARK in zk-STARK. Njihovo uporabno vrednost prikažemo na področju samo-upravljane in decentralizirane identitete ter na področju strojnega učenja. Pri decentralizirani identiteti ZKP omogočajo deljenje podatkov brez razkritja zasebnih informacij, medtem ko pri strojnem učenju omogočajo preverljivost izhodov modelov. To pomeni, da lahko uporabnik preveri, ali je bil za generiranje napovedi dejansko uporabljen pravilno izbran model.
At the current stage of autonomous driving, monitoring the behavior of safety stewards (drivers) is crucial to establishing liability in the event of an accident. However, there is currently no method for the quantitative assessment of safety steward behavior that is trusted by multiple stakeholders. In recent years, deep-learning-based methods can automatically detect abnormal behaviors with surveillance video, and blockchain as a decentralized and tamper-resistant distributed ledger technology is very suitable as a tool for providing evidence when determining liability. In this paper, a trusted supervision paradigm for autonomous driving (TSPAD) based on multimodal data authentication is proposed. Specifically, this paradigm consists of a deep learning model for driving abnormal behavior detection based on key frames adaptive selection and a blockchain system for multimodal data on-chaining and certificate storage. First, the deep-learning-based detection model enables the quantification of abnormal driving behavior and the selection of key frames. Second, the key frame selection and image compression coding balance the trade-off between the amount of information and efficiency in multiparty data sharing. Third, the blockchain-based data encryption sharing strategy ensures supervision and mutual trust among the regulatory authority, the logistic platform, and the enterprise in the driving process.
In the contemporary digital age, the authentication and verification of academic certificates have become increasingly vital yet challenging due to issues such as fraud, forgery, and the inefficiencies of traditional paper-based systems.This paper explored the implementation of blockchain technology as a robust solution for university certificate verification systems.Blockchain's decentralized, immutable ledger offers unparalleled security, transparency, and trust, making it an ideal framework for certifying academic credentials.By leveraging blockchain, universities can issue tamper-proof digital certificates that are easily verifiable by employers and other stakeholders, eliminating the need for intermediaries.This system enhances the reliability of academic records, reduces administrative burdens, and accelerates the verification process.Moreover, the paper discusses the technical architecture of a blockchain-based certificate system, including smart contracts, cryptographic techniques, and distributed consensus mechanisms.The paper analyze case studies of existing implementations to highlight the practical benefits and challenges encountered.The findings suggest that blockchain technology not only fortifies the integrity of academic certifications but also paves the way for a more efficient, transparent, and globally accessible verification infrastructure.This transformative approach has the potential to set new standards in academic administration and significantly curb credential fraud on a global scale.
Srikanthudu Avancha, Prof. Arpit Jain, Er. Om Goel
The rapid evolution of the IT sector has led to increasingly complex vendor management systems, necessitating innovative solutions to handle the multifaceted challenges associated with these systems. Traditional vendor management practices often struggle with issues related to transparency, security, inefficiencies in communication, and trustworthiness among vendors. Blockchain technology, with its decentralized, immutable, and transparent characteristics, presents a compelling solution to these challenges. This research paper explores the application of blockchain technology in IT vendor management, focusing on its potential to address critical challenges and enhance the overall efficiency of vendor-related processes. The paper begins by outlining the inherent challenges in conventional vendor management systems, including difficulties in verifying vendor credentials, managing contracts, ensuring data security, and maintaining a reliable audit trail. These challenges often result in operational inefficiencies, increased costs, and potential risks related to vendor fraud or non-compliance. Blockchain technology, known for its secure, transparent, and decentralized nature, offers a transformative approach to these challenges. By providing a distributed ledger that records all transactions in a secure and immutable manner, blockchain can significantly enhance the transparency and security of vendor management processes. The paper examines how blockchain can be used to automate vendor verification, streamline contract management through smart contracts, and ensure data integrity across the vendor lifecycle.
The combination of blockchain technology with federated learning (FL) introduces an innovative method to improve security, privacy, and trust in decentralized machine learning systems. Federated learning allows for distributed model training while safeguarding data privacy by keeping original data on local devices. Nonetheless, it confronts issues such as ensuring data integrity, the reliability of model updates, and vulnerability to adversarial attacks. Blockchain technology creates an immutable, decentralized ledger that guarantees transparency, secure aggregation, and verifiable updates to models. By utilizing blockchain's consensus protocols, smart contracts, and cryptographic methods, FL can counteract threats like poisoning attacks and eliminate single points of failure. This paper examines the architectural framework, advantages, and challenges of merging blockchain with FL, in addition to potential enhancements to boost scalability and efficiency. We also emphasize practical applications and prospective research pathways in this evolving field.
Keyword-based auditing (KA) provides a means for users to verify the integrity of only the outsourced data they are interested in. Existing KA schemes employ relation authentication labels to conduct targeted audits with keywords, which significantly improves the cost-effectiveness. However, such schemes typically support only a single-challenge scenario, which may not always be practical. To overcome this constraint, we introduce a hierarchical challenge mechanism grounded in user attributes. This mechanism leverages inequality and affiliation relationships to comply with a predefined tree structure for access policies. Incorporated during the challenge-response phase of the auditing model, it permits users to initiate cross-challenges. Expanding upon this hierarchical mechanism, we propose an attribute-based hierarchical keyword auditing scheme, abbreviated as$\mathcal{AHKA}$.$\mathcal{AHKA}$combines searchable encryption to conduct cross-targeted audits and benefits from the hash collision mapping of Bloom filters to safeguard against keyword guessing attacks. Moreover, we design a fault localization algorithm based on a variant of the binary search technique. It locates in batch the faulty cloud servers and damaged data blocks after an audit failure. As an integral part of$\mathcal{AHKA}$, the algorithm significantly enhances our scheme's practicability. Security analyses indicate that$\mathcal{AHKA}$can effectively withstand both forgery and replace attacks on audit proofs. The smart contract component ensures that our scheme's processes can be monitored and regulated. Experimental data corroborate that deploying$\mathcal{AHKA}$on the client side and on the blockchain is both efficient and feasible.
Proofs are powerful tools for integrity and privacy, enabling the verifier to delegate a computation and still verify its correct execution, and enabling the prover to keep the details of the computation private. Both CCP and ZKP can achieve soundness and zero-knowledge but with important differences. CCP relies on hardware trust assumptions, which yield high performance and additional confidentiality protection for the prover but may be unacceptable for some applications. CCP is also often easier to use, notably with existing code, whereas ZKP comes with a large prover overhead that may be unpractical for some applications.
As digital interactions continue to shift toward decentralized platforms, the limitations of centralized identity systems such as data silos, lack of user control, and reliance on intermediaries have become increasingly apparent. This research introduces a structured, multi-layered framework to support the design and implementation of trustless digital identity systems aligned with the principles of Web3. The proposed model integrates five core components: standardized identity protocols, regulatory alignment, user-centric design, trusted institutional participation, and enterprise integration through middleware. Each layer addresses critical challenges such as legal recognition, interoperability, usability, and system scalability. By combining decentralized technologies with practical governance and user experience strategies, the framework aims to enable secure, verifiable, and portable identities that function across jurisdictions and platforms. This paper offers a foundational approach to advancing digital identity infrastructure in a way that is technically robust and socially inclusive
Layer 2 solutions have emerged in recent years as a valuable alternative to increase the throughput and scalability of blockchain-based architectures. The three primary types of Layer 2 solutions are state channels, sidechains, and rollups. The rollups are particularly promising, allowing significant improvements in transaction throughput, security, and efficiency, and have been adopted by many real-world projects, such as Polygon and Optimistic. However, the adoption of Layer 2 solutions has led to other challenges, such as the data availability problem, where transaction data processed off-chain must be posted back on the main chain. This is crucial to prevent data withholding attacks and ensure all participants can independently verify the blockchain state. This paper provides a comprehensive survey of existing rollup-based Layer 2 solutions with a focus on the data availability problem and discusses the major advantages and disadvantages of them. Finally, an analysis of open challenges and future research directions is provided.
The emergence of vehicular applications such as collision warning enhances traffic efficiency and the driving experience of users. Due to the features of decentralization, complexity, and heterogeneity in intelligent transportation systems, the key issue is ensuring the legality and trustworthiness of all participating parties. Traditional methodologies such as public key infrastructure provide services for verifying the legitimacy of entities with certificates. However, even if a vehicle is legally registered, trust in its behavior is not always assured. Recently decentralized trust management systems (DTMS) are proposed to solve the trust issue. However, achieving both dependability and efficiency remains a challenge. In this paper, we propose a novel DTMS based on the consortium blockchain. We in particular focus on the dependability of trust evaluation, where trust computation is performed on both vehicles and RSUs. To achieve a sustainable trust environment, we propose an incentive model whereby the raters can earn rewards for providing honest ratings. Instead of utilizing the consensus algorithm based on the Proof of Work (PoW) or Proof of Stake (PoS), we implement a verifiable delay function (VDF)-based consensus model within the trusted execution environment (TEE) to ensure efficiency and security for the consortium blockchain. In addition, we design a smart contract on top of the blockchain to assist the system in detecting a specific attack against the trust system, known as the on-off attack. Through extensive experiments, the results of trust assessment and blockchain performance demonstrate the dependability and efficiency of our proposed DTMS.
Tatami puzzles are pencil puzzles with an objective to partition a rectangular grid into rectangular regions such that no four regions share a corner point, as well as satisfying other constraints. In this paper, we develop a physical card-based protocol called Tatami printer that can help verify solutions of Tatami puzzles. We then use the Tatami printer to construct zero-knowledge proof protocols for two such puzzles: Tatamibari and Square Jam. These protocols enable a prover to show a verifier the existence of the puzzles' solutions without revealing them.
Sharmila Subudhi, Mohd Aarif, Santosh Kumar, Dalia Younis · 7 authors
The conventional core digital identity management structure (DIMS) is vulnerable to hazards like disintegrated identity, single point of breakdown, inner assaults, and security leaks. Arising blockchain innovation enables DIMSs to be executed in it, which helps many of the issues triggered via the core 3rd party, yet its built-in openness and absence of security constitute significant challenges to DIMSs. In this context, this study uses smart contracts as well as zero-knowledge proof (ZKP) techniques to enhance the present assert identity framework on the blockchain to achieve identity unlink ability, successfully preventing the disclosure of characteristic possession. In addition, we apply BZDIMS, a framework model that enables users to specifically open up their control of characteristics to service providers to safeguard users’ conduct security. When contrasted with the previous framework, our approach accomplishes successful characteristic security safeguarding and a broader usage opportunity based on performance and security assessment.
In the contemporary landscape of the battlefield, the enhanced cyber warfare capabilities of adversaries mandate that routing protocols are equipped with endogenous security features. These features must be capable of detecting threats promptly and addressing them effectively to ensure both security and control. They also provide secure configuration options for the intrinsic security architecture of communication nodes within communication systems. This paper introduces a novel, inherently secure identity verification system named ORCA, which utilizes the concept of noninteractive zero-knowledge proof. ORCA streamlines the process of node identity authentication by minimizing communication exchanges, thereby safeguarding network topology integrity and establishing trust upon network formation. Leveraging this framework, the ORCA-OLSR security protocol was developed. Comparative simulations on the OPNET platform between the ORCA-OLSR and the challenge-response mechanism-based CA-OLSR security protocol demonstrate that ORCA-OLSR outperforms its counterpart in metrics such as routing overhead, end-to-end delay, and routing load.
Chihiro Kado, Naoto Yanai, Jason Paul Cruz, Kyosuke Yamashita · 5 authors
Vulnerabilities in Ethereum smart contracts often cause significant financial damage. Whereas the Solidity compiler has been updated to mitigate vulnerabilities, the effectiveness of these updates remains undisclosed to the best of our knowledge. In this paper, we aim to shed light on the impact of compiler versions on reducing vulnerabilities in Ethereum smart contracts. To achieve this, we collected 497,344 contracts with Solidity source codes from the Ethereum blockchain and analyzed their vulnerabilities. For three vulnerabilities of high severity, i.e., Locked Money , Using tx.origin , and Unchecked Call , we illustrate their appearance rate changes, showing decreases attributed to major updates of the Solidity compiler. Subsequently, we found the following four key insights. Firstly, updates to version 0.6 and version 0.8 led to decreased appearance rates for Locked Money . Secondly, regardless of compiler updates, the appearance rate for Using tx.origin was significantly low. Thirdly, the appearance rate for Unchecked Call significantly decreased from version 0.5 to version 0.8. Lastly, as an incidental discovery from our empirical study, we identified implications for code clones, which merit attention from subsequent researchers and developers.
Hussein Zangoti, Alex Pissinou Makki, Wazir Zada Khan, Niki Pissinou
The rapidly evolving mobile IoT landscape, driven by mobile financial applications, self-driving cars, wearables, and health monitoring devices, confronts substantial blockchain storage challenges due to decentralized networks, limited band-width, and high storage overhead. To tackle these issues, we propose the Collective Signing-Based Blockchain Storage Optimization (CSBSO) algorithm. CSBSO mitigates storage over-head by leveraging the Collective Signing (CoSi) protocol and employing a multidimensional blockchain structure for efficient block management and retrieval. It focuses on identifying and pruning irrelevant blocks and implementing streamlined data management. Evaluations with Ethereum Classic Blockchain and Facebook Users datasets show CSBSO achieves up to 92% storage optimization, surpassing current models. These results underscore the effectiveness of CoSi-based strategies in reducing blockchain storage overhead in resource-constrained environments.