Blockchain Papers

Vassilis Papaspirou, Ioanna Kantzavelou, Yagmur Yigit, Λέανδρος Μαγλαράς · 5 authors

The evolution of authentication mechanisms in ensuring secure access to systems has been crucial for mitigating vulnerabilities and enhancing system security. However, despite advancements in two-factor authentication (2FA) and multi-factor authentication (MFA), authentication mechanisms remain weak in system security, particularly when individuals accessing critical systems are involved. In response to this challenge, we propose a novel blockchain-based multi-factor dynamic authentication mechanism (BMFA) that integrates honeytoken technology to enhance security. Our proposed mechanism leverages Ethereum blockchain technology and smart contracts to provide a decentralized and robust authentication framework. By incorporating honeytokens into smart contracts, we introduce a dynamic layer of security that continuously adapts to prevent potential attacks. Our evaluation demonstrates that our BMFA mechanism effectively addresses various security challenges, including brute force attacks, man-in-the-middle attacks, and smart contract vulnerabilities, while providing robust protection against unauthorized access. Our findings emphasise the efficacy of the BMFA mechanism in enhancing system security and mitigating evolving threats in authentication processes for next-generation critical industrial control systems.

Samuel de Oliveira Ribeiro, Dayan Ramos Gomes, Nara Raquel D. Andrade, Emanuel Aurélio F. de Miranda · 5 authors

Non-fungible Tokens (NFTs) are digital objects with unique identities and ownership verified via blockchain networks. The digital arts and media industry has embraced NFTs for their secure features, such as defining authorship, transfer, and royalties, which can be programmed into smart contracts. The classification of NFTs is crucial for their commercialization but often relies on the author’s definition, which may be prone to errors, or on expert evaluation. In this work, we analyze NFT collection classes based on metadata extracted from OpenSea, the largest NFT platform. We assess the efficiency of supervised machine learning to identify the most relevant attributes of these collections and classify them into the nine most popular categories on the platform. Our results demonstrate the challenges of automating classification to assist users and platform curators, achieving a promising accuracy of 67% and an F1 score of 72% in the best cases.

Milan Feltovic

Blockchain technology has evolved from its origins in cryptocurrencies to become a fundamental component of secure digital interactions across diverse sectors, including healthcare, finance, and public administration. This article delves into the theoretical and practical applications of cryptography within blockchain networks, emphasizing key cryptographic functions, algorithms, and protocols such as RSA, elliptic curve cryptography (ECC), and SHA-256. It scrutinizes the use of digital signatures for transaction verification and the crucial role of hash functions in ensuring data integrity. Additionally, the article presents practical examples of symmetric and asymmetric encryption methods, underscoring their significance in maintaining privacy and security. The study also highlights the emerging challenges posed by quantum computing and explores ongoing research in post-quantum cryptography. Furthermore, it provides insights into the advancements in cryptographic techniques essential for the robustness of decentralized networks. By linking theoretical frameworks with practical implementations, this article aims to offer a comprehensive understanding of the cryptographic security measures pivotal for the future of blockchain technology.

Rui Pan, Zeshun Shi, Adam Belloum, Zhiming Zhao

Preserving privacy in blockchain-based systems is crucial for ensuring anonymity and confidentiality during transactions. While cryptographic solutions can address on-chain privacy concerns, their implementation on blockchains may introduce performance overhead, which remains unclear to researchers and practitioners. This paper investigates the performance impact of integrating zero-knowledge proofs (ZKPs) into the widely adopted permissioned blockchain framework called Hyperledger Fabric. The study focuses on evaluating the scalability and bottleneck aspects of blockchain platforms incorporating ZKPs. Through comprehensive experimentation and analysis, the study reveals that the integration of ZKPs compromises performance in terms of transaction rates and latency, while effectively safeguarding users’ personal information. Implementing on-chain ZKP feature would result in a performance loss of 30% to 87.5% in various experimental configurations in Hyperledger Fabric. The findings presented in this paper are informative for the design and implementation of blockchain-based systems with strict privacy requirements.

Chunjie Guo, Lin You, Xingyu Li, Gengran Hu · 6 authors

Biometric authentication is a very convenient and user-friendly method. The popularity of this method requires strong privacy-preserving technology to prevent the disclosure of template information. Most of the existing privacy protection technologies rely on classic encryption techniques, such as homomorphic encryption, which incur huge system overhead and cannot be popularized. To address these issues, we propose a novel biometric authentication scheme with privacy protection based on support vector machine and zero knowledge proof (BioAu–SVM+ZKP). BioAu–SVM+ZKP allows users to authenticate themselves to different service providers without disclosing any biometric template information. The evidence is generated through the zero-knowledge proof utilizing polynomial commitments. Our approach for generating a unique and repeatable biometric identifier from the user’s fingerprint image leverages the multi-classification property of SVM. Notably, our scheme not only reduces the communication overhead but also provides the privacy protection features. Besides, the communication overhead of BioAu–SVM+ZKP is constant. We have simulated the authentication scheme on the common dataset NIST, analyzed the performance and proved the security.

Qi Liang, Ning Shi, Yu‐an Tan, Chunying Li · 5 authors

With the widespread adoption of blockchain technology, its public ledger characteristic enhances transaction transparency but also amplifies the risk of privacy breaches. Attackers can infer users’ real identities and behaviors by analyzing public transaction patterns and address relationships, posing a severe threat to users’ privacy and security, and thus hindering further advancements in blockchain applications. To address this challenge, covert communication has emerged as an effective strategy for safeguarding the privacy of blockchain users and preventing information leakage. But existing blockchain-based covert communication schemes rely solely on the immutability of blockchain itself for robustness and suffer from low transmission efficiency. To tackle these issues, this paper proposes a stealthy communication model with blockchain smart contract for bidding systems. The model initiates by preprocessing sensitive information using a secret-sharing algorithm-the Shamir (t, n) threshold scheme-and subsequently embeds this information into bidding amounts, facilitating the covert transfer of sensitive data. We implemented and deployed this model on the Ethereum platform and conducted comprehensive performance evaluations. To assess the stealthiness of our approach, we employed a suite of statistical tests including the CDF, the Kolmogorov–Smirnov test, Welch’s t-test and K–L divergence. These analyses confirmed that amounts carrying concealed information were statistically indistinguishable from regular transactions, thus validating the effectiveness of our solution in maintaining the anonymity and confidentiality of information transmission within the blockchain ecosystem.

Mritunjay Shall Peelam, Gaurav Kumar, Kunjan Shah, Vinay Chamola

Abstract Online voting is gaining traction in contemporary society to reduce costs and boost voter turnout, allowing individuals to cast their ballots from anywhere with an internet connection. This innovation is cautiously met due to the inherent security risks, where a single vulnerability can lead to widespread vote manipulation. Blockchain technology has emerged as a promising solution to address these concerns and create a trustworthy electoral process. Blockchain offers a decentralized network of nodes that enhances transparency, security, and verifiability. Its distributed ledger and non‐repudiation features make it a compelling alternative to traditional electronic voting systems, ensuring the integrity of elections. To further bolster the security of online voting, we propose DemocracyGuard platform on the Ethereum blockchain, which incorporates facial recognition technology to authenticate voters. By leveraging these advancements, DemocracyGuard aims to provide a secure and resilient platform for online voting, paving the way for its broader adoption and revolutionizing the electoral landscape.

Daiki Miyahara, Léo Robert, Pascal Lafourcade, Takaaki Mizuki

A Zero-Knowledge Proof (ZKP) protocol allows a participant to prove the knowledge of some secret without revealing any information about it. While such protocols are typically executed by computers, there exists a line of research proposing physical instances of ZKP protocols. Up to now, many card-based ZKP protocols for pen-and-pencil puzzles, like Sudoku, have been designed. Those games, mostly edited by Nikoli, have simple rules, yet designing them in card-based ZKP protocols is non-trivial. In this work, we propose a card-based ZKP protocol for Usowan, a Nikoli game. In Usowan, for each room of a puzzle instance, there is exactly one piece of false information. The goal of the game is to detect this wrong data amongst the correct data and also to satisfy the other rules. Designing a card-based ZKP protocol to deal with the property of detecting a liar has never been done. In some sense, we propose a physical ZKP for hiding of a liar. This work extends a previous paper appearing in Ref. [1]. In this extension, we propose two other protocols, for Herugolf and Five Cells. The puzzles are specifically chosen because each of those three puzzles shares a common constraint, connectivity. However, showing the connected configuration cannot be done with generic approach and brings new construction to the existing connectivity ZKP protocol. Indeed, in Herugolf, the connectivity is handled with a given length of cell which is decremental (i.e., the length of each connected cell decreases by one at each step). For Five Cells, there is an additional step in the setup allowing to encode all the information needed to ensure a valid ZKP protocol.

Iosif Polenakis, Vasileios Vouronikos, Eftychia Kiafa, Maria Chroni · 5 authors

Non-Fungible Tokens (or, for short, NFT) establish the ownership and the authenticity of digital assets. Regardless the high security levels provided by blockchain, are not excluded the cases where the ownership of a digital object may be claimed without proper rights. Fraud and copyright infringement should be prevented through the insurance of the authenticity and the integrity of a digital object associated with an NFT. In this work we consider the case of NFT images under the aspect of being susceptible to duplication, theft, tampering, fraud, or in general any potential threat against their authenticity and integrity properties. To deal with such cases we propose an integrated system that provides an a priori embedding of authenticity and integrity related information by deploying robust authenticity information hiding in the frequency domain alongside fragile integrity information hiding in the spatial domain before the image is being publicly available as NFT. Moreover, an automated secure procedure for the development of smart contracts alongside the development of an NFT dual that serves as backup and is not publicly available through the marketplace is proposed in order to retain the initial digital image. We design a modular architecture that incorporates all the components proposed in this work and discuss its potentials on its deployment over different digital objects that can be considered as NFTs.

Saeed Bamashmos, Naveen Chilamkurti, Ahmad Salehi Shahraki

Internet of Things (IoT) technology is evolving over the peak of smart infrastructure with the participation of IoT devices in a wide range of applications. Traditional IoT authentication methods are vulnerable to threats due to wireless data transmission. However, IoT devices are resource- and energy-constrained, so building lightweight security that provides stronger authentication is essential. This paper proposes a novel, two-layered multi-factor authentication (2L-MFA) framework using blockchain to enhance IoT devices and user security. The first level of authentication is for IoT devices, one that considers secret keys, geographical location, and physically unclonable function (PUF). Proof-of-authentication (PoAh) and elliptic curve Diffie-Hellman are followed for lightweight and low latency support. Second-level authentication for IoT users, which are sub-categorized into four levels, each defined by specific factors such as identity, password, and biometrics. The first level involves a matrix-based password; the second level utilizes the elliptic curve digital signature algorithm (ECDSA); and levels 3 and 4 are secured with iris and finger vein, providing comprehensive and robust authentication. We deployed fuzzy logic to validate the authentication and make the system more robust. The 2L-MFA model significantly improves performance, reducing registration, login, and authentication times by up to 25%, 50%, and 25%, respectively, facilitating quicker cloud access post-authentication and enhancing overall efficiency.

Matthew Marcellino, Arya Wicaksana, Moeljono Widjaja

The advancement of blockchain technology introduces the new concept of electronic voting systems (e-voting) that are fully anonymous, transparent, trustless, and decentralized. The limitation of blockchain-based e-voting systems is the need for initial setup to verify and validate eligible voters. This initial setup requires human intervention, which curbs the full potential and exploitation of blockchain technology. Identity authentication is crucial in voting systems to ensure the eligibility of the voters and the validity of the results. This paper proposes a hybrid approach using ZK-SNARK for identity authentication systems in blockchain-based e-voting. The proposed hybrid approach aims to maintain the benefit of blockchain technology while guaranteeing the eligibility of voters. Both on-chain and off-chain identity authentication modules are designed and developed to balance the trade-off of centralized and decentralized nature for the blockchain-based e-voting systems. The affordability of the proposed system is essential in justifying the approach's feasibility and usability. Voting systems are expected to host thousands to millions of voters, and the cost is one major consideration. The proposed system is deployed in the Ethereum blockchain network, including its sidechain and Layer 2, i.e., Avalanche, Arbitrum One, and Polygon. The gas fee required for the smart contract deployment in Ethereum is USD12.5, while the lowest gas fee is in the Polygon blockchain network for USD0.02.

Dr.Satyanarayana A

Online voting is a trend that is gaining momentum in modern society. It has great potential to decrease organizational costs and increase voter turnout. It eliminates the need to print ballot papers or open polling stations—voters can vote from wherever there is an Internet connection. Despite these benefits, online voting solutions are viewed with a great deal of caution because they introduce new threats. A single vulnerability can lead to large-scale manipulations of votes. Electronic voting systems must be legitimate, accurate, safe, and convenient when used for elections. Nonetheless, adoption may be limited by potential problems associated with electronic voting sys-tems . Blockchain technology came into the ground to overcome these issues and offers decentralized nodes for electronic voting and is used to produce electronic voting systems mainly because of their end-to-end verification advantages. This technology is a beautiful replacement for traditional electronic voting solutions with distributed, non-repudiation, and security protection characteristics. The following article gives an overview of electronic voting systems based on blockchain technology. The main goal of this analysis was to examine the current status of blockchain-based voting research and online voting systems and any related difficulties to predict future developments. This study provides a conceptual description of the intended blockchain-based electronic voting application and an introduction to the fundamental structure and characteristics of the blockchain in connection to electronic voting. As a consequence of this study, it was discovered that blockchain systems may help solve some of the issues that now plague election system

Kannan Balasubramanian

The article delves into the intricate characteristics and security properties of the secp256k1 elliptic curve used for the generation of addresses in the Bitcoin blockchain. The Bitcoin blockchain is a decentralized digital ledger that records all transactions made with Bitcoin cryptocurrency. In this work, the secp256k1 elliptic curve and its parameters and the method of generating private and public keys using random numbers are described. While the private key allows for the signing of transactions to spend Bitcoin, the corresponding public key and address enable others to verify transactions and send funds to that specific address on the blockchain, ensuring security, authenticity, and privacy in the decentralized network. The attacks on the use of secp256k1 for generating the bitcoin addresses like the Brute force attack, twist attack, fault attacks, and side channel attacks in the implementation of the elliptic curve are discussed. By maintaining the security and integrity of secp256k1, we can ensure that cryptographic operations, such as digital signatures and key exchanges, remain uncompromised. If the curve's security were compromised, malicious users could potentially derive private keys from public keys, leading to unauthorized transactions, double-spending, or other malicious activities. The security of implementation can be enhanced by ensuring cryptographic libraries and software implementations that utilize secp256k1 undergo thorough testing and validation to ensure correct and secure operations. The important attacks on blockchain technology like the 51% attack, Sybil attack, Double Spending attack, and Smart Contract vulnerabilities are discussed. Through a comprehensive exploration, readers will gain insights into why this particular elliptic curve was chosen for use in Bitcoin's cryptographic protocols, highlighting its role in ensuring the robustness and integrity of the blockchain ecosystem.

Daniel Commey, Sena Hounsinou, Garth V. Crosby

This paper presents a framework for securing blockchain-based IoT systems by integrating Physical Unclonable Functions (PUFs) and Zero-Knowledge Proofs (ZKPs) within a Hyperledger Fabric environment. Our approach leverages PUFs for robust device authentication and ZKPs for privacy-preserving transaction processing, addressing key challenges of security, privacy, and scalability in IoT systems. The framework’s architecture utilizes Hyperledger Fabric’s modular design and private channels to enhance scalability. Off-chain experimental results demonstrate the framework’s feasibility, with compact proof sizes (median 805 bytes) and efficient processing times (average 2,800 ms end-to-end). A comprehensive security analysis shows the framework’s resilience against various attacks, including device impersonation and data tampering. This work provides a foundation for secure and scalable blockchain-based IoT systems, with directions for future on-chain implementation and optimization for resource-constrained devices.

Wenyue Wang, Biwei Yan, Baobao Chai, Ruiyao Shen · 6 authors

In the Internet of Things (IoT), a large number of devices are connected using a variety of communication technologies to ensure that they can communicate both physically and over the network. However, devices face the challenge of a single point of failure, a malicious user may forge device identity to gain access and jeopardize system security. In addition, devices collect and transmit sensitive data, and the data can be accessed or stolen by unauthorized user, leading to privacy breaches, which posed a significant risk to both the confidentiality of user information and the protection of device integrity. Therefore, in order to solve the above problems and realize the secure transmission of data, this paper proposed EBIAS, a secure and efficient blockchain-based identity authentication scheme designed for IoT devices. First, EBIAS combined the Elliptic Curve Cryptography (ECC) algorithm and the SHA-256 algorithm to achieve encrypted communication of the sensitive data. Second, EBIAS integrated blockchain to tackle the single point of failure and ensure the integrity of the sensitive data. Finally, we performed security analysis and conducted sufficient experiment. The analysis and experimental results demonstrate that EBIAS has certain improvements on security and performance compared with the previous schemes, which further proves the feasibility and effectiveness of EBIAS.

Shaoqi Yuan, Wenzhong Yang, Xiaodan Tian, Wenjie Tang

With the continuous advancement of information technology, a growing number of works, including articles, paintings, and music, are being digitized. Digital content can be swiftly shared and disseminated via the Internet. However, it is also vulnerable to malicious plagiarism, which can seriously infringe upon the rights of creators and dampen their enthusiasm. To protect creators’ rights and interests, a sophisticated method is necessary to authenticate digital intellectual property rights. Traditional authentication methods rely on centralized, trustworthy organizations that are susceptible to single points of failure. Additionally, these methods are prone to network attacks that can lead to data loss, tampering, or leakage. Moreover, the circulation of copyright information often lacks transparency and traceability in traditional systems, which leads to information asymmetry and prevents creators from controlling the use and protection of their personal information during the authentication process. Blockchain technology, with its decentralized, tamper-proof, and traceable attributes, addresses these issues perfectly. In blockchain technology, each node is a peer, ensuring the symmetry of information. However, the transparent feature of blockchains can lead to the leakage of user privacy data. Therefore, this study designs and implements an Ethereum blockchain-based intellectual property authentication scheme with privacy protection. Firstly, we propose a method that combines elliptic curve cryptography (ECC) encryption with digital signatures to achieve selective encryption of user personal information. Subsequently, an authentication algorithm based on Zero-Knowledge Succinct Non-Interactive Argument of Knowledge (zk-SNARK) is adopted to complete the authentication of intellectual property ownership while encrypting personal privacy data. Finally, we adopt the InterPlanetary File System (IPFS) to store large files, solving the problem of blockchain storage space limitations.

Franco Frattolillo

In a global context characterized by a pressing need to find a solution to the problem of digital copyright protection, buyer-seller watermarking protocols based on asymmetric fingerprinting and adopting a “buyer-friendly” approach have proven effective in addressing such a problem. They can ensure high levels of usability and security. However, they usually resort to trusted third parties (TTPs) to guarantee the protection process, and this is often perceived as a relevant drawback since TTPs may cause conspiracy or collusion problems, besides the fact that they are generally considered as some sort of “big brother”. This paper presents a buyer-seller watermarking protocol that can achieve the right compromise between usability and security without employing a TTP. The protocol is built around previous experiences conducted in the field of protocols based on the buyer-friendly approach. Its peculiarity consists of exploiting smart contracts executed within a blockchain to implement preset and immutable rules that run automatically under specific conditions without control from some kind of central authority. The result is a simple, usable, and secure watermarking protocol able to do without TTPs.

Yuxuan Zhou, Jiaqi Chen, Yibo Wang, Yuzhe Tang · 5 authors

In public blockchains, leaking secret keys can cause the permanent loss of crypto assets. It is imperative to understand the illicit activities on blockchains related to leaked keys. This paper presents the first measurement study that uncovers, quantifies, and characterizes the actual misuses of the leaked keys from top websites on the Internet to withdraw assets on Ethereum. By finding key-leaking web pages and joining them with transactions, the study reveals 7.29*10^6/0.59*10^6 USD worth of assets on Ethereum mainnet/Binance Smart Chain (BSC) are withdrawn from 1421/1514 leaked secret keys. Mitigations are proposed to avoid the financial loss caused by leaked keys.

Zhenshuai Yue, Haoran Zhu, Xiaolin Chang, Jelena Mišić · 6 authors

Traditional covert transmission (CT) approaches have been hindering CT application while blockchain technology offers new avenue. Current blockchain-based CT approaches require off-chain negotiation of critical information and often overlook the dynamic updating of session keys, which increases the risk of message and key leakage. Additionally, in some approaches the covert transactions exhibit obvious characteristics that can be easily detected by third-parties. Moreover, most approaches do not address the issue of decreased reliability of message transmission in blockchain attack scenarios. Bitcoin-and Ethereum-based approaches also have the issue of transaction linkability, which can be tackled by Monero-based approaches because of the privacy protection mechanisms in Monero. However, Monero-based CT has the problem of sender repudiation. In this paper, we propose a novel$M$onero-$B$ased CT approach (MBCT), which enables on-chain session key dynamically updating without off-chain negotiation. MBCT can assure confidentiality of on-chain session key, non-repudiation of transmission parties, reliability of message transmission under blockchain attack, unlinkability and obscurity of covert transactions. They are achieved by the three components in MBCT, namely, a sender authentication method, a dynamically on-chain session key updating method and a state feedback method. We implement MBCT in Monero-0.18.1.0 and the experiment results demonstrate its high embedding capacity of MBCT.

Mrs. K. Divya Kalyani, S. Aimen Fathima, Sowndarya Lakshmi, K.S. Hemanth · 5 authors

This paper introduces a novel Digitalized Voting System designed to address the shortcomings of current voting methods employed in India. With a focus on enhancing transparency and trust in the electoral process, the system aims to overcome challenges present in both traditional and digital voting systems, including instances of mishaps and injustice. Leveraging blockchain technology, the proposed system seeks to ensure fair elections and minimise occurrences of injustice. While electronic voting has been introduced as a solution to paper-based voting, it has encountered obstacles primarily related to security and privacy concerns. To address these issues, our framework emphasises the effectiveness of various components such as the polling process, hashing algorithms, contract and block creation, data accumulation, and result declaration.Utilising an adjustable blockchain method, the system aims to provide a robust solution to the security and data management challenges inherent in blockchain technology. By incorporating elements such as blockchain, hashing algorithms, block creation, OTP verification, and Ethereum, our approach endeavours to digitalize the voting process comprehensively. This paper contributes to the advancement of electoral integrity by presenting an improved manifestation of electronic voting, paving the way for more transparent and secure elections

S. V. Padmavathi Devi, Mr Alangaram S, Mrs Sangeetha D, S. Jeeva · 5 authors

The healthcare sector has witnessed a rapid digitization of patient records, leading to an exponential increase in the volume and sensitivity of healthcare data.However, ensuring the security and privacy of this data has emerged as a critical challenge due to the evolving landscape of cyber threats.To address this challenge, a novel approach that combines the scalability of cloud computing with the immutability and transparency of blockchain technology to achieve robust security for healthcare data.The proposed hybrid storage framework leverages the advantages of both cloud computing and blockchain to establish a secure and efficient data management system.In this framework, sensitive healthcare data is encrypted and stored on distributed cloud servers to ensure high availability and reliability.Additionally, a blockchain-based distributed ledger is employed to record access logs and maintain a tamper-proof audit trail of data transactions.The integration of blockchain technology enables transparent and accountable data sharing among authorized parties while preserving patient privacy and confidentiality.The results indicate that the hybrid storage model offers superior resilience against various security threats, including unauthorized access, data breaches, and tampering, thus ensuring the confidentiality, integrity, and availability of healthcare data.

Aditi Singh

The "Immutable Identity Validation System: A Blockchain and Soulbound Token Approach" paper introduces an innovative method for verifying digital identities. By combining blockchain technology and Soulbound Tokens (SBTs), it enhances security and privacy in identity verification processes. SBTs, designed as non-transferable and tamper-proof digital assets, play a crucial role in bolstering the security and reliability of the system. Their unique properties ensure that user privacy is prioritized while also facilitating swift verification through blockchain transparency. This approach addresses the growing demand for robust identity verification solutions, particularly in sectors like education and corporations, where fraud prevention and streamlined processes are critical. The methodology involves various steps, including SBT generation, blockchain integration, user control mechanisms, and stringent security measures. Both frontend and backend development, along with the integration of blockchain using tools like Ganache and decentralized data storage through IPFS, contribute to building a secure and user-friendly system. Thorough testing, documentation, and knowledge transfer are essential to ensuring the system's reliability, security, and compliance with legal standards. Ultimately, the goal is to establish a globally accepted framework for identity verification in today's interconnected digital landscape. Keywords:; privacy; security; Blockchain; Cryptography; Decentralization; Soul Bound Token (SBT), distributed ledger.

Sangeeta Gupta, Ramu Kuchipudi, Md Sohail, Karan Singh · 6 authors

Counterfeit products have become a significant problem for small and medium-sized businesses (SMBs), with the estimated value of counterfeit goods worldwide reaching trillions of dollars. However, SMBs often lack the resources and technical expertise to implement sophisticated anti-counterfeiting measures. Towards this end, the work proposes a blockchain-based solution named as Fake Product Identification for Small and Medium Firms (FPISMF) using Hyperledger and AES encryption to enable SMBs to identify fake products and protect their brand reputation. The details of the products and the details of customers are encrypted using AES encryption and recorded on the blockchain. The application communicates with the blockchain network to validate the product and retrieve the details of the product. Chaincode is executed in a containerized environment, which provides isolation and security for the code and data being processed. An algorithm is also proposed to substitute the missing QR-code bits and data that helps reduce customer wait time. Experiments are conducted on synthesized data sets and results showing the effectiveness of the proposed FPISMF framework and reconciliation technique. It is observed from the results that though the time taken to replace a blurry bit is greatly reduced as compared to manual replacement of the product, there is an increase in this time when associated with encryption while extraction of the corresponding code from cloud database thereby achieving a time complexity of O(n), where ‘n’ is the number of scanned products. In addition, the AES SMB time complexity is approximately recoded as O(n/2) and the Cloud access and retrieval time is O(n) as compared to O(2n) in the existing work. This shows a significant improvement in the ability to replace missing bits and perform a secure analysis respectively.

Marwan Adnan Darwish, Georgios Smaragdakis

The virtue of data forgetting has become a substantial demand in the digital era. Once online content has served its purpose, the concept of forgetting arises to ensure that data remains private between data owners and service providers. Despite significant advancements in supporting data forgetting through approaches like access heuristics, elastic expiration times, and manual revocation, the existing research falls short in addressing the demand for a multi-level forgetting structure that can cater to diverse audience-based expiration requirements while considering additional criteria. To the best of our knowledge, no prior works have investigated this gap, emphasizing the need for a comprehensive solution that can effectively accommodate the varying expiration needs of different audience groups. In this paper, we introduce a novel disjunctive multi-level forgetting scheme designed to meet the aforementioned demand for data forgetting. Our scheme introduces unique expiration periods for the encrypted data the service provider stores, called levels. Users are grouped into different levels based on priorities assigned by the data owners. Each level corresponds to a specific expiration threshold, enabling designated user groups to access the content within its validity period before it is forgotten. This approach enables selective data forgetting for one group while enabling concurrent access and retention for other user groups until the stipulated expiration period elapses. To achieve this, we have devised a cutting-edge system that integrates a hierarchical and dynamic scheme utilizing a key decay for managing expiration periods. Moreover, we introduce an innovative approach that harnesses smart contracts on a local Ethereum blockchain to enforce regulations and streamline the secure and efficient expiration and deletion of data. Finally, we thoroughly evaluate our proposed scheme, focusing on decay sensitivity, computational complexity, and rigorous security analysis.