Blockchain Papers

Xueqing Zhao, Hao Liu, Shuning Hou, Xin Shi · 6 authors

No abstract is available for this record.

Chaya Ganesh, Claudio Orlandi, Daniel Tschudi, Aviv Zohar

No abstract is available for this record.

Houyu Zheng, Lin You, Gengran Hu

It is crucial to ensure the privacy and authenticity of patients’ medical data in the medical insurance claim process, but in the current medical insurance claim process, there are some problems such as low efficiency, complex service, unreliable data and data leakage. Therefore, considering the privacy and sensitivity of patients’ medical data, we can improve the current issues by employing blockchain, smart contracts and zero-knowledge proof technology. In this paper, we propose a novel medical insurance claim scheme based on smart contracts, blockchain and zero-knowledge proof. Our scheme mainly involves two scenarios: medical insurance purchasing and medical insurance claiming. In the privacy-preserving transaction phases of the two scenarios, we can ensure the legitimacy and privacy of the transactions between the patients and the insurance companies by using a non-interactive zero-knowledge proof and the homomorphic encryption algorithm under the Decisional Bilinear Diffie–Hellman (DBDH) assumption. In the identity privacy-preserving phases of the two scenarios, we can ensure the legitimacy and the privacy of patients’ identities by integrating Schnorr protocol and Fiat–Shamir heuristic method. The security analysis, the computation cost and the communication cost of our scheme are given. Compared with our referred schemes, the performance evaluation shows that our scheme not only meets the requirements of the legality of the medical insurance claim, but also ensures the authenticity and privacy of the patients’ medical data. Moreover, the experimental results demonstrate that our scheme is feasible and has an acceptable time overhead.

Yinjie Gong, Y. J. Jin, Yuchan Li, Ziyi Liu · 5 authors

Thanks to the development in encryption technology and blockchain, cryptocurrency has already proven feasible and applicable. However, blockchain requires massive information including details of every transaction, the information of the dealer and buyer, which makes the privacy of every user on blockchain vulnerable. With the presence of Zcash, a new concept called Zero-Knowledge proof which focuses on proving and verifying identities appears in front of every researcher and engineer working on blockchain. Because of the enormous quantity of the ZKP schemes and the limited time, in this article, we have compared four main ZKP algorithms-ZK-SNARK, ZK-STARK, MPC protocol-based algorithms, and Bulletproof. By comparing these algorithms, we intend to give relevant engineers and researchers a general understanding of the advantages and disadvantages of these algorithms. In addition, we try to make the relevant people aware of the application scenarios of each ZKP.

Miroslav Stefanović, Đorđe Pržulj, Sonja Ristić, Darko Stefanović · 5 authors

Land administration systems are of great importance for a large number of stakeholders. One of the key problems related to land administration systems is the problem of the correctness of their state, meaning that data stored in land administration systems are not in concordance with the actual legal, spatial and topographic situation. The main causes of land administration systems’ incorrect state are data collection and compilation, data processing, and data misuse. In this paper, we discuss the problems of data tampering, the long time needed for registering land administration system’s transactions, and the possibility of double spending, which all can add incorrectness in a land administration system. Our research is based on the hypothesis that these problems may be addressed by means of distributed ledger technology, or to be more precise, by means of blockchain technology. The solution is presented in a form of a smart contract written in Solidity programing language that can cover even those more specific use cases in land administration systems such as sharing of ownership, transferring part of ownership, splitting or merging of real estate, and limiting the possibility of trading a real estate. The proposed smart contract represents an implementation of a programming interface that was created based on both ERC-20 and ERC-721 token standards, to satisfy the specific needs of land administration systems.

Saroj Kumar Nanda, Sandeep Kumar Panda, Madhabananda Das, Suresh Chandra Satapathy

No abstract is available for this record.

Yueyue He, Jiageng Chen

No abstract is available for this record.

Vedran Juričić, Danijel Kučak, Goran Đambić

No abstract is available for this record.

Yanjiao Chen, Yuyang Ran, Jingyue Zhou, Jian Zhang · 5 authors

Blockchain-based cryptocurrencies are severely limited in transaction throughput and latency due to the need to seek consensus among all peers of the network. A promising solution to this issue is payment channels, which allow unlimited numbers of atomic and trust-free payments between two peers without exhausting the resources of the blockchain. A linked payment channel network enables payments between two peers without direct channels through a series of intermediate nodes that forward and charge for the transactions. However, the charging strategies of intermediate nodes vary with different payment channel networks. Existing works do not yet have a complete routing algorithm to provide the most economical path for users in a multi-charge payment channel network. In this work, we propose MPCN-RP, a general routing protocol for payment channel networks with multiple charges. Our extensive experimental results on both simulated and real payment channel networks show that MPCN-RP significantly outperforms the baseline algorithms in terms of time and fees.

Tonino Palmisano, Vito Nicola Convertini, Lucia Sarcinella, Luigia Gabriele · 5 authors

In traditional notarization processes, the correctness of the activities between the parties is guaranteed by a central authority or guaranteeing institution. In this case, the authority is not able to quickly establish the originality of the content to be notarized, or at least to have a large degree of certainty without the use of automated systems. This paper presents a new notarization platform that uses blockchain technology and integrates advanced anti-plagiarism approaches able to effectively detect copyright violations of documents that users want to notarize. In addition, our proposal includes the use of models, methods, and techniques, through which a very high level of privacy and information security can be guaranteed.

Tahmid Hasan Pranto, Abdulla All Noman, Mustafizur Rahaman, AKM Bahalul Haque · 6 authors

E-commerce platforms have made our life easier and bought plenty of advantages too. However, due to fraud and scams, trust is a concern while buying products online. In this study, we proposed a blockchain-based architecture for the e-commerce sector where data mining technology is used to detect fraudulent users by generating precise and effective rules, and smart contracts are used for enforcement and functionality management within the blockchain network. Our data mining approach yielded a competitive accuracy, precision, recall, and f1-measure of over 99% compared to the state-of-the-art. High performing rules are further tested for ten simulated cycles under completely unseen data to test their rigidity in a real-time scenario. Details analysis of delineation (if any) in rule antecedents has also been analyzed for these cycles. Tested and selected rules are stored in smart contracts deployed within blockchain network for security and immutability. For ensuring strict order criteria maintenance, better return policy, authentic review and scam avoidance, two smart contracts have been written which implement seller reputation mechanism and authentic review maintenance while safeguarding the seller from intentional defaming too. Altogether, the goal of this study is to establish a balance between all the parties within an e-commerce platform so that everyone's right is protected, money is safe and resources are not exploited.

Tuan‐Vinh Le, Chien-Lung Hsu, Chen Wei-xin

In the era of Industry 4.0 and digital transformation, smart grid (SG) plays an important role in the construction of various smart places. Logs produced by electrical appliances recording power consumption within the grid contain private information and may be collected as evidence for the services of dispute resolution or digital forensics. Therefore, security of the logs is of paramount importance. Our work designs a blockchain-enabled log management scheme with nonrepudiation for SGs. In this article, we employ ciphertext-policy attribute-based encryption to establish a fine-grained access control of the logs, which addresses data confidentiality concern. In addition, we introduce a hybrid blockchain system generating novel signature chains, for achieving an efficient private log protection system with a lot of properties including data loss prevention, tamper resistance, immutability and nonrepudiation. Employing various cost-saving solutions, our scheme achieves an efficient communication with more functionalities and security features, compared with the predecessor works.

Sahaya Ashwini, Annapurna P Patil, Savita K. Shetty

Over the last few years, the world has been moving towards digital healthcare, where harnessing medical data distributed across multiple healthcare providers is essential to achieving personalized treatments. Though the efficiency and speed of the diagnosis process have increased due to the digitalization of healthcare data, it is at constant risk of cyberattacks. Medical images, in particular, seem to have become a regular victim of hackers, due to which there is a need to find a feasible solution for storing them securely. This work proposes a blockchain-based framework that leverages the InterPlanetary File system (IPFS) to provide decentralized storage for medical images. Our proposed blockchain storage model is implemented in the IPFS distributed file-sharing system, where each image is stored on IPFS, and its corresponding unique content-addressed hash is stored in the blockchain. The proposed model ensures the security of the medical images without any third-party dependency and eliminates the obstacles that arise due to centralized storage.

Franco Frattolillo

Copyright protection of digital content has become a problem not only for web content providers but also for ordinary web users who like to publish their digital contents on social or user generated content platforms. Among the possible solutions to such a problem, digital watermarking, in conjunction with watermarking protocols, appears to be a valid alternative to current DRM (digital rights management) systems. In fact, watermarking based solutions insert perceptually invisible copyright information into the copies of contents published or distributed on the web in order to track them. Such insertions are carried out according to the watermarking protocols, which have evolved over the years from the classic “buyer and seller” paradigm into a simpler and versatile “buyer friendly” and “mediated” approach. However, such an approach cannot exploit the new technologies that characterize the current Internet. This paper presents a new watermarking protocol able to adapt the “buyer friendly” and “mediated” approach to the use of innovative technologies such as cloud platforms and blockchain. In this way, (1) content providers and common web users can take advantage of the computing and storage resources made available by cloud platforms; (2) the involvement of trusted third parties in the protocols can be reduced by using blockchain without complicating the protection scheme. In fact, these two goals make the protocol particularly suited for the current Internet.

Lu Lin, Baocheng Wang

More and more countries are exploring smart city related smart facilities to benefit the society. Remote access and control of IOT smart devices is convenient, but there are also some risks. Smart devices may be attacked by criminals who will do serious harm to the production environment. It is particularly important to design a safe and efficient secure communication scheme. Most existing solutions to this problem are usually based on single server architecture, which has some problems in security and efficiency. Aiming at the problem that authentication and key agreement in smart water conservancy are vulnerable to SPOF and DDOS attacks, this paper proposes an authentication key agreement technology based on blockchain. In key agreement, the identity of smart devices can not be tampered with, which can effectively resist man in the middle attack. In the process of protocol execution, the nodes of smart devices are light nodes. The process of key agreement is carried out in the smart contract, which reduces the computational complexity and improves the operation efficiency. This paper also analyzes the security of the scheme.

Dariel Bobadilla, Carlo Lipizzi

Blockchain has enabled businesses to innovate by creating a decentralized system that transforms power affects a wide range of industries, including banking, finance, manufacturing, supply chain management, healthcare, and government. Many industries, including e-commerce, could use this model to promote scalability, security, and decentralization. We are entering a new age of information sharing powered by blockchain technology. Building trust in distributed environments without relying on authorities represents a technological advance that could transform many industries, including recommendation systems. A new and advanced way of exploring Blockchain and recommendation systems (RS) will be explored in this research. We propose a decentralized recommendation system by formulating a decentralized matrix completion form based on the popular collaborative filleting (CF) model by incorporating it into a decentralized network. Our goal is to make online activities more secure and trusted by incorporating smart contracts in the main blockchain protocol. Using blockchain technology in recommendation systems, we will be able to make online activities more secure. A smart contract system is created that enables enterprises to use a secure database to cooperate and continuously maintain an updated model. As part of the learning case studies, a collaborative filtering model is used for recommendation purposes along with the decentralized concept of blockchain for storage and computation in such a way that data is fully distributed. An incentive mechanism evaluates the model accuracy by offering a trust-based, high-performing recommendation system.

Jashan Khangura, Jatin Arora

Cryptocurrency is a digital asset that works through distributed ledger technology such as a blockchain. Blockchain was dubbed as un-hackable by many, but recent incidents indicate that it is not the case. This paper aims to examine different types of cyberattacks. Attacking cryptocurrencies is much more intriguing to criminals, mainly because of the reason that reverting those funds is a laborious task in itself. This paper surveys 5 different kinds of cryptocurrency attacks and also examines different consensus algorithms used by cryptocurrencies. Despite blockchain being a leading edge technology, the vulnerabilities in the technology has caused difficulties in the past and cannot be ignored.

Haifeng Wang, Junguo Liao

Due to the transparency of the blockchain, the data in the blockchain can be viewed by any joining node, and the privacy is weak. In order to better solve the problem of privacy protection in the current blockchain, for the application of e-commerce blockchain, the Pedersen commitment mechanism is adopted to hide the transaction amount, combined with zero-knowledge proof technology to realize the verification of the transaction amount. At the same time, an efficient range proof scheme based on polynomial commitment and vector inner-product commitment is used to verify whether the transaction amount and the balance of both parties are greater than zero. Finally, use the homomorphism promised by Pedersen to update the ciphertext ledger. The security analysis and efficiency test of the proposed blockchain privacy protection algorithm show that compared with the existing schemes, the proposed algorithm has the advantages of strong security and higher efficiency.

P Subha, P. Padmasree, Sowndharya Lakshmi R

The Voting System in India is often corrupted and altered. The idea is to create an unbiased, secure, fast and efficient Voting System. This project is based on the domain of Block Chain wherein the voting database will be highly secure and processed quickly. The Iris Recognition is another aspect of this system which makes the process flawless. The usage of Blockchain based Database to store the data will make the voting information immutable, reliable and can be quickly accessed. The authorized results tracking makes the voting process more secure, quick and efficient since it is semi-automated. The Iris Recognition identifies the unique patterns of Irises using infrared light and generates an encrypted bit pattern which should match at the time of voting, in order to confirm the individual's identity is true. The process of Iris Scanning is backed up with fingerprint recognition exclusively for blind voting candidates since their Iris pattern may not be measured precisely by the Iris Recognition System.

Esra Günsay, Cansu Betin Onur, Murat Cenk

Zero-knowledge protocols (ZKPs) allow a party to prove the validation of secret information to some other party without revealing any information about the secret itself. Appropriate, effective, and efficient use of cryptographic ZKPs contributes to many novel advances in real-world privacy-preserving frameworks. One of the most important type of cryptographic ZKPs is the zero-knowledge range proofs (ZKRPs). Such proofs have wide range of applications such as anonymous credentials, cryptocurrencies, e-cash schemes etc. In many ZKRPs the secret is represented in binary then committed via a suitable commitment scheme. Though there exist different base approaches on bilinear paring-based and RSA-like based constructions, to our knowledge there is no study on investigating the discrete logarithm-based constructions. In this study, we focus on a range proof construction produced by Mao in 1998. This protocol contains a bit commitment scheme with an OR-construction. We investigate the effect of different base approach on Mao's range proof and compare the efficiency of these basis approaches. To this end, we have extended Mao's range proof to base-3 with a modified OR-proof. We derive the number of computations in modulo exponentiations and the cost of the number of integers exchanged between parties. Then, we have generalized these costs for the base-u construction. Here, we mainly show that comparing with other base approaches, the base-3 approach consistently provides approximately 12% efficiency in computation cost and 10% efficiency in communication cost. We implemented the base-3 protocol and demonstrated that the results are consistent with our theoretical computations.

Saumya Bhadauria, Pranjal Kumar, Tamanna Mohanty

Most of the digital systems completely ignore the generation of the watermark and how the watermark will be stored, while developing strong watermarking algorithms to avoid the unauthorized replication of the same asset. In this paper, a framework scheme based on digital watermarking using blockchain technology is proposed for protecting the digital assets of Intellectual Property. Blockchain is used to store the transaction details and the watermark information helps us track the asset's ownership transfer and provides authentication of the watermark. This work demonstrates an implementation of the light and efficient functions, i.e., image hashing using the Wavelet hash function, storing hashed information of the owner and the digital assets using a Quick Response Code, and enables watermarked image storage using the IPFS. We demonstrate that the blockchain can also be used to record the transfer of the asset from one owner to another. One of the takeaways from this proposal is that the elimination of the third-party results in fewer data and copyright leaks which in turn makes the system more reliable and secure. In fact, it speeds up the process of the ownership transfer of the assets.

Chengkai Rao, Zhaowen Lin

The traditional public key infrastructure (PKI) issues certificates by trusted certification authority (CA). But due to the centralized structure of CA, it brings some problems, such as single-point failure, certificate opacity and so on. Another decentralized system web of trust (WOT) has a high access threshold. In addition, WOT cannot ensure the authenticity of users’ authentication because of lack of incentive, and it cannot authenticate the specific user identity. In this paper, we propose a new distributed identification system based on blockchain, called VAPKI. This system is implemented through smart contracts on Ethereum, which is transparent and immutable. Meanwhile, it can authenticate the fine-grained attributes of user identity and strengthen the authenticity of user identity through transparent authentication. In addition, VAPKI can identify the malicious user through the regular validation tasks (RVTs). In addition, it realizes the credit and deposit mechanism, ensuring users to be honest and trustworthy. This mechanism can also force users to authenticate strictly and punish malicious users found in RVTs.

Shanyun Huang, Wenyin Zhang, Xiaomei Yu, Jiuru Wang · 6 authors

Due to the unique characteristics of blockchain, such as decentralization, anonymity, high credibility, and nontampering, blockchain technologies have become an integral part of public data platforms and public infrastructure. The communication between the stakeholders of a given blockchain can be used as a carrier for covert communication under cover of legal transactions, which has become a promising research direction of blockchain technology. Due to the special mechanism of blockchain, some traditional blockchain covert communication schemes are not mature enough. They suffer from various drawbacks, such as weak concealment of secret information, cumbersome identification and screening of special transactions, poor availability, and low comprehensive performance. Therefore, this paper designs a scheme of covert communication in the Bitcoin blockchain, which takes normal transactions as a mask and leverages the Bitcoin transaction mechanism to embed secret information in the public key hash field. Specifically, we propose a novel key update mechanism combined with the hash algorithm to construct a covert channel. It ensures security and can update the channel to prevent the related problems caused by address reuse. We are taking advantage of the feature of Bitcoin that cannot be double-spent to solve the problem of burning bitcoin when paying bitcoin to a fake public key hash. In our scheme, both parties to the communication are anonymous, and the attacker cannot detect the covert data or track the transaction and address. Our proposed scheme was tested in real Bitcoin blockchain network, and the experimental results were analyzed to verify its security, availability, and efficiency.

Lu Ding, Yong Zhao

Selfish mining has potential hazards to blockchain systems by hiding mined blocks and broadcasting them strategically. It lets the adversary gain additional rewards in the mining process which was first proposed in Bitcoin recommended by Satoshi Nakamoto. The blockchain-based application Ethereum using GHOST (Greedy Heaviest-Observed Sub-Tree) protocol with regard to Bitcoin to alleviate the loss of honest miners of stale blocks and compensate uncle blocks which will increase if selfish mining occurs. But it only makes things worse since uncle incentive mechanism reduces the cost of the failure of selfish mining and decreases the threshold of selfish mining pool needed to be profitable. There is no research which focuses on the rationale behind uncle incentive mechanism in Ethereum. This paper focuses on the feasible modifications on uncle incentive mechanism against selfish mining in Ethereum. The uncle block reference behaviors of miners are analyzed when selfish mining occurs in Ethereum by building models. Furthermore, a feasible uncle incentive mechanism against selfish mining is proposed. It is not necessary to have a strategy with a monotonous order with regard to generations of uncle blocks. The uncle incentive mechanism suggested in this paper can efficiently raise the threshold for selfish mining to be profitable by around 3.17%, an increase by around 9.76%. It offers an alternative uncle incentive mechanism for cryptocurrencies which are based on GHOST protocol.