Blockchain Papers

G. Balamurugan, Amit Kumar Tyagi, Richa Richa

Blockchain technology has gained significant attention in recent years due to its decentralized and immutable nature, and has made itself ideal for various applications such as finance, supply chain management, and healthcare. However, privacy and trust issues have emerged as major challenges in blockchain-based systems/applications. This work provides a detailed explanation of the existing privacy-preserving and trust-building techniques in blockchain-based systems. The authors begin by discussing the fundamental concepts of blockchain technology and its features that affect privacy and trust. Further, they discuss the privacy challenges faced by blockchain systems. Various privacy-preserving techniques, such as encryption, zero-knowledge proofs, and mix-zones, are explained in detail (with highlighting their strengths and limitations). In addition to privacy, trust is an important aspect of blockchain-based systems.

Fehmi Jaafar, Darine Amayed, Wissam Salhab, Hajer Bouani · 5 authors

Video cameras are becoming ubiquitous. They'd be interconnected within a larger pervasive infrastructure supported by artificial intelligence which helps ensure smart services relaying in real-time video analysis and image processing. However, such services and technologies involve a set of privacy concerns. If privacy concerns can be addressed, enabling real-time analytics on video streams in public spaces can be valuable in supporting many applications for security, public safety, and urban space management. This study aims to highlight privacy concerns in image and video processing in the context of intelligent IoT systems by proposing a blockchain-based approach for data transparency and privacy management. As a result, our proposed approach will provide IoT customers the ability to manage their consent using a distributed ledger securely.

Saptarsi Saha, Himanshu Gupta, Nama Ravi Teja, Soumya Kothari · 5 authors

Many users upload documents to the cloud to be shared and verified by third-party people before they get access to digital services, e.g. opening a bank account, healthcare service, and making payments online. The documents include everything from a UID (unique identifying digit), Know your customer (KYC), company data, and files are uploaded and verified at a significant rate by an authorized third party. This process involves the transfer of sensitive data over the internet, and tracking the usage of the data by the users is almost impossible. This poses a significant disadvantage for the user as he/she cannot know if the data is being used for the intended purpose or not. The proposed approach in this paper provides secure data transfer to the intended party as well as a way to verify that the intended third party is only accessing the data for the intended purpose. With the use of smart contracts in this approach, the document can be masked with some random content when the intended task is completed and can provide a means to check if the data is being used for the intended purpose or not. It is found from the results that the proposed approach performs better than the existing approaches in terms of computational cost and monetary cost. Also, the overall execution time of the document verification process is improved, and would also allow the user to track the status of the document in the verification process with the help of the status tab.

Geunyoung Kim, Jae‐Cheol Ryou

Anonymity forms the basis of decentralized ecosystems, leading to an increase in criminal activities such as money laundering and illegal currency trading. Especially in blockchain-based metaverse services, activities such as preventing sexual crimes and verifying the identity of adults are becoming essential. Therefore, avatar authentication and the KYC (Know Your Customer) process have become crucial elements. This paper proposes a mechanism to achieve the KYC process by verifying user identity using smart contracts. Users obtain an SBT (Soul Bound Token) from the metaverse service provider through the DID (Decentralized Identity) credential issued during the KYC process. The identity verification of avatars occurs within smart contracts, ensuring user privacy and protection through ZKP (Zero Knowledge Proof). Tools for generating ZKP are also provided, enabling users, even those who are unfamiliar with ZKP, to use them conveniently. Additionally, an integrated wallet is offered to seamlessly manage DID credentials and SBTs. Furthermore, in case of avatar identity issues, users can request an audit by the issuer through the associated DID tokens.

Najmath Ottakath, Abdulla Al‐Ali, Somaya Al-Máadeed, Omar Elharrouss · 5 authors

Videos and image processing have significantly transformed computer vision, enabling computers to analyze, and manipulate visual data. The proliferation of cameras and IR equipment has facilitated the collection of valuable information about individuals and their surroundings. These technologies find applications in various domains, ranging from biometric entry cards and high-security clearances to surveillance. These applications form part of the Internet of Things (IoT), forming a centralized network. However, the proliferation of data and its sharing brings challenges related to security, privacy, and storage. Interactions with third-party systems may introduce vulnerabilities. To address these issues, researchers in computer vision have explored the integration of blockchain technology into various applications. This paper presents a comprehensive survey of blockchain applications in computer vision, focusing on image and video data sharing, video surveillance, biometrics, and video integrity protection. The aim is to explore how the blockchain can enhance the security, privacy, and authentication of them. It also discusses tools and techniques employed at the edge to achieve these objectives while highlighting opportunities for further improvements. Overall, this review provides insights into the integration of blockchain and computer vision, advancements, challenges, and future directions in leveraging image and video data in a blockchain-enabled environment.

Excelcius Ferdian Roni, Calandra Alencia Haryani, Arnold Aribowo, Aditya Mitra

Since the internet's emergence, numerous facets of daily life have evolved, including online investment opportunities. Cryptocurrency investment has gained popularity in this digital era. Prospective investors now have various cryptocurrencies to choose from, tailored to their preferences. Due to the volatility of cryptocurrency market, investors need to have careful consideration of which cryptocurrency to be chosen including its related decision to be made during their investment. One crucial consideration in this selection process is assessing fellow investors' opinions, often found on social media. This study employs text mining, using the k-means clustering algorithm to explore prevailing sentiments among cryptocurrency investors. The data source consists of Twitter comments on three prominent cryptocurrencies, Bitcoin, Ethereum, and Binance totaling 55,651 tweets. The findings predominantly reveal neutral sentiments towards these cryptocurrencies. Notable positive sentiment topics for Bitcoin include “worth” and “new,” while negative sentiments revolve around “firm” and “bank,” and neutral sentiments are linked to “digital” and “year.” Ethereum exhibits positive sentiments like “good” and “defi,” negative sentiments such as “time” and “long,” and neutral sentiments around “price” and “ethic”. Binance's positive sentiments include “live” and “kind,” a negative sentiment related to “case,” and neutral sentiments encompassing “learn” and “check”. Moreover, the Davies Bouldin Index evaluation for the coin clusters yielded scores of 0.7996 for Bitcoin, 0.7820 for Ethereum, and 0.7149 for Binance. These indices, falling between 0 and 1, signify well-structured clustering.

Aditya Sharma, Brijesh Kumar Chaurasia

No abstract is available for this record.

Rosa Pericàs-Gornals, Macià Mut–Puigserver, M. Magdalena Payeras–Capellà, Miquel À. Cabot-Nadal · 5 authors

Digital credentials are being issued by authorized entities to facilitate the digital identification of their users. They can be classified in identity credentials, academic and professional credentials, and access credentials. Blockchain offers some inherent features that are highly advantageous for the management of credentials. Non-Fungible Tokens, or NFTs, might seem to be a perfect fit for the implementation of digital credentials. However, some crucial requirements for credentials are the non-transferability of the credential and that the authorized entity can receive explicit acceptance from the user who will own the new credential. Nevertheless, there is a new type of token, named Soulbound tokens (SBT), that has been designed to ensure the non-transferability of assets. This paper presents a protocol that is focused on the issuance of digital access credentials, with the additional ability to allow the association of terms and conditions that users must accept when receiving these credentials. We use an enhanced version of the SBTs, called RejSBTs, to represent the credentials and associated terms, providing non-repudiation of reception and origin proofs.

Awatef Salem Balobaid, Yasamin Alagrash, Ali Fadel, Jamal N. Hasoon

Blockchain technology can be employed in the education sector by building a decentralized system to store and share student records. The records can be encrypted to guarantee their confidentiality and security. With a blockchain-based system, student records can be saved in blocks that are linked and secured via cryptography. The records are decentralized and not controlled by any single entity, making them less susceptible to hacking or tampering. By using blockchain technology, educational institutions can create a more secure and efficient system for storing and sharing student records. This can streamline the process of transferring records between schools, and provide a secure and transparent way for students to access their own records. In this study, we provide a novel Merkle tree-based strategy for preserving the accuracy of student records and outline how to put it into practice. The software architecture resembled blockchain technology and was developed for private network deployment. The key components of our strategy are replacing conventional audit trails with their cryptographically secure equivalent and simplifying the Blockchain framework by avoiding mining. The cryptography system's framework is presented, and the new five dimensions of chaotic map academic records are proposed. Our study utilizes deoxyribonucleic acid (DNA) sequences and operations and the chaotic system to strengthen the cryptosystem in the blockchain authentication and authorization process. The significant advantage of this method is enhancing the generation of the hash function, which is the most critical challenge in the blockchain concept. The experimental outcomes and security analysis demonstrated that the proposed method works well in terms of different aspects. The suggested hash function's hash value distribution, sensitivity to tiny message modifications, confusion and diffusion qualities, resilience against birthday attacks, keyspace analysis, collision resistance, efficiency, and flexibility were all considered throughout the study.

Ruta Jawale, Dakshita Khurana

A non-interactive ZK (NIZK) proof enables verification of NP statements without revealing secrets about them. However, an adversary that obtains a NIZK proof may be able to clone this proof and distribute arbitrarily many copies of it to various entities: this is inevitable for any proof that takes the form of a classical string. In this paper, we ask whether it is possible to rely on quantum information in order to build NIZK proof systems that are impossible to clone. We define and construct unclonable non-interactive zero-knowledge arguments (of knowledge) for NP, addressing a question first posed by Aaronson (CCC 2009). Besides satisfying the zero-knowledge and argument of knowledge properties, these proofs additionally satisfy unclonability. Very roughly, this ensures that no adversary can split an honestly generated proof of membership of an instance $x$ in an NP language $\mathcal{L}$ and distribute copies to multiple entities that all obtain accepting proofs of membership of $x$ in $\mathcal{L}$. Our result has applications to unclonable signatures of knowledge, which we define and construct in this work; these non-interactively prevent replay attacks.

Zhang Dayong, Nur Haliza Abdul Wahab, Khairunnisa A. Kadir, Arafat Al-Dhaqm · 6 authors

Blockchain is a distributed database technology developed because of cryptocurrency, which has the characteristics of open and transparent ledger data. However, attackers will analyze ledger data to obtain sensitive information, threatening transaction privacy of users. Cryptography is the underlying technology of the blockchain to ensure the integrity and legitimacy of transactions in the blockchain. Providing privacy protection for the blockchain by studying cryptography has become a research hotspot in the blockchain. This paper introduces the cryptography technology in the blockchain, summarizes the privacy protection problems existing in the current blockchain, and expounds the existing cryptography solutions and the advantages and disadvantages of each scheme. Finally, the future research directions of cryptography in blockchain are summarized and prospected.

Amjad Aldweesh

No abstract is available for this record.

Shunrong Jiang, Jinpeng Li, Xiaoyan Zhang, Hao Yue · 6 authors

The large-scale integration of decentralized energy resources has resulted in surgical changes in energy trading systems. Traditional centralized trading systems suffer from high management costs and low efficiency. The recent advance in blockchain technology has enabled the invention of decentralized energy trading systems, which can overcome the limitations of centralized trading systems. However, security and privacy concerns have become obstacles when widely marketing and implementing decentralized energy trading systems. For example, the on-chain transactions are publicly visible, leading to the risk of trading information leakages. Moreover, in the demand response (DR) assistance process, the aggregated report of energy trading results may contain detailed trading information which results in user privacy leakage. To address those problems, this article proposes a blockchain-based privacy-aware energy trading mechanism. We design a stealthy on-chain transmission method to protect user privacy without revealing the consumer-supplier trading relationship and the exact trading data. Furthermore, we employ non-interactive zero-knowledge (NIZK) proof to aggregate reports in a reliable and privacy-preserving manner. Security analysis and experimental results demonstrate that the proposed mechanism can achieve security goals with affordable cost for decentralized energy trading systems.

Akihiro Fujihara

In Bitcoin Core (BTC), there exists an upper limit of the block size around 1MB, which causes the Bitcoin scalability problem that severely limits transaction processing capacity.On the other hand, Bitcoin SV (BSV) forked from BTC is known to eliminate this limit.In BSV, the size of mined blocks is generally not uniform, but a mixture of various different sizes.Block miners in BSV can get more transaction fees as a reward, while there is a risk that the success rate of block mining decreases because it has to take a longer time to verify all the transactions in the block.For this reason, the selection of block size depends on mining strategy of each miner.To the best of our knowledge, there has been no detailed report on how each miner selects a block size.In this paper, we firstly formulated the Bitcoin scalability problem using a mathematical model of transaction processing capacity.Then, we investigated the probability distributions of block size in both Scaling Test Network (STN) and Mainnet of BSV.As a result, we found that the aggregate block size distribution in STN follows an exponential distribution, while that in the Mainnet follows a power-law distribution whose exponent is around one.We demonstrated a theoretical explanation of the difference between two distributions in the STN and Mainnet with a unified manner based on an underlying incentive mechanism.

Lucas Mayr, Lucas Palma, Gustavo Zambonin, Wellington Fernandes Silvano · 5 authors

Private key management is a complex obstacle arising from the traditional public key infrastructure model. However, before any related security breach can be addressed, it must first be reliably detected. Certificate Transparency (CT) is an example of a certificate issuance monitoring strategy, developed to detect the possible malfeasance of certification authorities (CAs). To the best of our knowledge, CT and other detection mechanisms do not cover digitally signed documents made by an end user, which are also susceptible to CA misbehavior. We modify the CT framework to handle signed documents via logging certificates in the blockchain to enable the secure and user-friendly monitoring of one-time signatures, backdating protection, and effective CA misbehavior detection. Moreover, to demonstrate the feasibility of our proposal, we present distinct deployment scenarios and analyze the storage, performance, and monetary costs.

Joel Herve Mboussam Emati, Hedgar Plessy Mboussam, Vianney Kengne Tchendji

In this paper, we focus on blockchain-based mechanisms for securing self-sovereign digital identities of people (physical and legal). These solutions almost all depend on the near-daily use of Internet of Things (IoT) devices that themselves produce huge amounts of data while being resource constrained. We support the idea of integrating artificial intelligence as a mandatory step in the blockchain management process and the use of lightweight cryptography in zero-knowledge proofs. In essence, we identify at least eight attack vectors on self-sovereign identities and classified how these vectors could be secured using the two techniques.

Sunil Kumar, Aman Singh, Abderrahim Benslimane, Premkumar Chithaluru · 7 authors

No abstract is available for this record.

Lin Wang, Changgen Peng, Weijie Tan

Blockchain integrates peer-to-peer networks, distributed consensus, smart contracts, cryptography, etc. It has the unique advantages of weak centralization, anti-tampering, traceability, openness, transparency, etc., and is widely used in various fields, e.g., finance and healthcare. However, due to its open and transparent nature, attackers can analyze the ledger information through clustering techniques to correlate the identities between anonymous and real users in the blockchain system, posing a serious risk of privacy leakage. The ring signature is one of the digital signatures that achieves the unconditional anonymity of the signer. Therefore, by leveraging Distributed Key Generation (DKG) and Elliptic Curve Cryptography (ECC), a blockchain-enabled secure ring signature scheme is proposed. Under the same security parameters, the signature constructed on ECC has higher security in comparison to the schemes using bilinear pairing. In addition, the system master key is generated by using the distributed key agreement, which avoids the traditional method of relying on a trusted third authorizer (TA) to distribute the key and prevents the key leakage when the TA is not authentic or suffers from malicious attacks. Moreover, the performance analysis showed the feasibility of the proposed scheme while the security was ensured.

Saeed Banaeian Far, Seyed Mojtaba Hosseini Bamakan

Abstract A considerable number of people worldwide start their second lives in the digital world soon. The 3D Internet reflects the digital world. Metaverse, the most famous example of the 3D Internet, is very popular and practical in people’s daily lives. However, combining Metaverse with newly-emerging technologies (e.g., blockchain) provides new user-friendly features such as autonomy, accessibility, removing central authorities, etc. Despite the mentioned attractive features, blockchain-based metaverses suffer various challenges, such as one user with multiple identities, certificate issuing for users in Metaverse, authentication-related issues, and arresting malicious users. Generally, identity management in a distributed environment where no central authority exists is a challenging issue. This study focuses on the challenge of distributed identity management in Metaverses to strike a balance between users’ privacy and regulation. The study proposes the use of Non-Fungible Tokens (NFTs) as a tool for managing identities in metaverses, as they are considered an excellent choice for this purpose. In addition to explaining the importance of this idea, this paper identifies its challenges, including distributed identity management, authentication issues, and security and privacy aspects. It then proposes possible solutions (e.g., using cryptographic tools). Despite existing challenges, there are many opportunities in the popularization of Metaverse, such as relying on blockchain technology, emerging many Metaverse-related jobs, in-Metaverse investments for huge revenues, and applying digital twins to provide realistic senses. This study also highlights the critical role of artificial intelligence (AI) in metaverses.

Xinyu Yi, Yuping Zhou, Yuqian Lin, Ben Xie · 6 authors

No abstract is available for this record.

Vinay Gugueoth, Sunitha Safavat, Sachin Shetty, Danda B. Rawat

IoT security is one of the prominent issues that has gained significant attention among the researchers in recent times. The recent advancements in IoT introduces various critical security issues and increases the risk of privacy leakage of IoT data. Implementation of Blockchain can be a potential solution for the security issues in IoT. This review deeply investigates the security threats and issues in IoT which deteriorates the effectiveness of IoT systems. This paper presents a perceptible description of the security threats, Blockchain based solutions, security characteristics and challenges introduced during the integration of Blockchain with IoT. An analysis of different consensus protocols, existing security techniques and evaluation parameters are discussed in brief. In addition, the paper also outlines the open issues and highlights possible research opportunities which can be beneficial for future research.

Niraj Anil Patil, Nikhil B. Khandare

Non-Fungible Tokens (NFTs) are cryptographic assets on a blockchain. Blockchain by definition is a public ledger. NFTs are becoming a tool to collect and share digital art as well as providing an investment opportunity. Most NFT Marketplaces are built on top of popular blockchains which are not equipped with privacy tools. As a result, NFTs are publicly visible. This poses an issue when the owner wants limit the access to their NFTs. This research aims to build a system to tackle this problem. Specifically, it will use the Public Key Encryption Algorithm: RSA to limit the access to the NFT.

Goshgar Ismayilov, Can Özturan

Blockchains are decentralized and immutable databases that are shared among the nodes of the network. Although blockchains have attracted a great scale of attention in the recent years by disrupting the traditional financial systems, the transaction privacy is still a challenging issue that needs to be addressed and analysed. We propose a Private Token Transfer System (PTTS) for the Ethereum public blockchain in the first part of this paper. For the proposed framework, zero-knowledge based protocol has been designed using Zokrates and integrated into our private token smart contract. With the help of web user interface designed, the end users can interact with the smart contract without any third-party setup. In the second part of the paper, we provide security and privacy analysis including the replay attack and the balance range privacy attack which has been modelled as a network flow problem. It is shown that in case some balance ranges are deliberately leaked out to particular organizations or adversial entities, it is possible to extract meaningful information about the user balances by employing minimum cost flow network algorithms that have polynomial complexity. The experimental study reports the Ethereum gas consumption and proof generation times for the proposed framework. It also reports network solution times and goodness rates for a subset of addresses under the balance range privacy attack with respect to number of addresses, number of transactions and ratio of leaked transfer transaction amounts.

Kasun Moolika Gedara, Minh Nguyen, Weiqi Yan, Xue Jun Li

In this paper, we explore video blockchain for establishing connectivity among vehicles in a smart city through utilizing blockchain technology. By leveraging intelligent vehicular systems that provide location-based visualization through multiple deployed cameras in vehicles, we expand the scope of collecting video surveillance data for observation, thereby enhancing overall situational awareness. We utilize the decentralized nature of blockchain to implement a vehicle-based surveillance system across a smart city. To ensure reliability, the integration of two cryptographic functions, hashing and signing, with the blockchain is employed. This integration ensures secure and tamper-proof solutions for the existing intelligent surveillance system. In this paper, our primary focus is on combining blockchain technology to achieve sustainable and robust smart solutions for intelligent vehicular distributed video networks while eliminating the need for third-party intermediaries. Through extensive experiments and analysis, we demonstrate the effectiveness and feasibility of our proposed video blockchain approach. The results indicate that this innovative framework provides enhanced security, privacy, and scalability for intelligent vehicular distributed networks in smart cities, paving the way for a connected and efficient urban environment.