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Chicaiza, Silvana Abigail Yacchirema, Chafla, Ciro Napoleon Saguay, Álvarez, Luis Fernando Enriquez, Matute, Polo Fabian Iñiguez, Rodriguez, Ramiro Delgado.  2021.  Analysis of information security in the PoW (Proof of Work) and PoS (Proof of Stake)blockchain protocols as an alternative for handling confidential nformation in the public finance ecuadorian sector. 2021 16th Iberian Conference on Information Systems and Technologies (CISTI). :1–5.
Blockchain technology relies on a growing number of globally distributed ledgers known as blockchain. This technology was used for the creation of the cryptocurrency known as bitcoin that allows transactions to be carried out quickly and easily, without the need to use an intermediary "financial institution". The information is sent trough the protocols known as: PoW (Proof of Work) and PoS (Proof of Stake), which must guarantee confidentiality, integrity and availability of the information. The present work shows the result of a bibliographic review on the evolution of the blockchain, the PoW and PoS protocols; as well as the application of these within the framework of Ecuadorian legislation with emphasis on the evolution of risks of the PoW protocol.
Alshahrani, Waleed, Alshahrani, Reem.  2021.  Assessment of Blockchain Technology Application in the Improvement of Pharmaceutical Industry. 2021 International Conference of Women in Data Science at Taif University (WiDSTaif ). :1–5.
Blockchain technology (BCT) has paved a way for new potentials of handling serious data privacy, integrity and security issues in healthcare. To curb the increasing challenges in healthcare industry, healthcare organizations need to apply blockchain technology to better improve patient safety and protect patients records from counterfeiting and fraud. The purpose of this research paper was to define BCT can assist in improving pharmaceutical industries in Saudi Arabia upon utilization of its application. This study adopted quantitative methods to gather the study data. Based on healthcare leaders perception and Internet connection, lack of cooperation, and economic inequality were found to be leading factors hindering the application of blockchain technology in the pharmaceutical industries, Saudi Arabia. Factors facilitating the application of blockchain technology in the pharmaceutical industries, Saudi Arabia were found as system robustness of BCT, increased data safety and decentralization, need for enhanced supply chain management and interoperability, and government laws and policies. Adopting interventions that are targeted to specific patient population medications, effective delivery systems, transit provider reimbursement far from intensity and volume of services towards value and quality was found to compromise the pre-existent challenges and real capacity in healthcare system. Although the relationship between implementation of blockchain technology and cost spending is negative in the short-term, in the long run, the relationship is positive Blockchain helps in managing multiple levels in a more secure way, reduces paper work and amplifies verification inefficiency.
Garrocho, Charles Tim Batista, Oliveira, Karine Nogueira, Sena, David José, da Cunha Cavalcanti, Carlos Frederico Marcelo, Oliveira, Ricardo Augusto Rabelo.  2021.  BACE: Blockchain-based Access Control at the Edge for Industrial Control Devices of Industry 4.0. 2021 XI Brazilian Symposium on Computing Systems Engineering (SBESC). :1–8.
The Industrial Internet of Things is expected to attract significant investments for Industry 4.0. In this new environment, the blockchain has immediate potential in industrial applications, providing unchanging, traceable and auditable access control. However, recent work and present in blockchain literature are based on a cloud infrastructure that requires significant investments. Furthermore, due to the placement and distance of the cloud infrastructure to industrial control devices, such approaches present a communication latency that can compromise the strict deadlines for accessing and communicating with this device. In this context, this article presents a blockchain-based access control architecture, which is deployed directly to edge devices positioned close to devices that need access control. Performance assessments of the proposed approach were carried out in practice in an industrial mining environment. The results of this assessment demonstrate the feasibility of the proposal and its performance compared to cloud-based approaches.
Lahbib, Asma, Toumi, Khalifa, Laouiti, Anis, Martin, Steven.  2021.  Blockchain Based Privacy Aware Distributed Access Management Framework for Industry 4.0. 2021 IEEE 30th International Conference on Enabling Technologies: Infrastructure for Collaborative Enterprises (WETICE). :51–56.
With the development of various technologies, the modern industry has been promoted to a new era known as Industry 4.0. Within such paradigm, smart factories are becoming widely recognized as the fundamental concept. These systems generate and exchange vast amounts of privacy-sensitive data, which makes them attractive targets of attacks and unauthorized access. To improve privacy and security within such environments, a more decentralized approach is seen as the solution to allow their longterm growth. Currently, the blockchain technology represents one of the most suitable candidate technologies able to support distributed and secure ecosystem for Industry 4.0 while ensuring reliability, information integrity and access authorization. Blockchain based access control frameworks address encountered challenges regarding the confidentiality, traceability and notarization of access demands and procedures. However significant additional fears are raised about entities' privacy regarding access history and shared policies. In this paper, our main focus is to ensure strong privacy guarantees over the access control related procedures regarding access requester sensitive attributes and shared access control policies. The proposed scheme called PDAMF based on ring signatures adds a privacy layer for hiding sensitive attributes while keeping the verification process transparent and public. Results from a real implementation plus performance evaluation prove the proposed concept and demonstrate its feasibility.
Maria Stephen, Steffie, Jaekel, Arunita.  2021.  Blockchain Based Vehicle Authentication Scheme for Vehicular Ad-hoc Networks. 2021 IEEE Intelligent Vehicles Symposium Workshops (IV Workshops). :1–6.
Vehicular Ad Hoc Network (VANET) is a pervasive network, where vehicles communicate with nearby vehicles and infrastructure nodes, such as Road-side unit (RSU). Information sharing among vehicles is an essential component of an intelligent transportation system (ITS), but security and privacy concerns must be taken into consideration. Security of the network can be improved by granting access only to authenticated vehicles and restricting or revoking access for vehicles involved in misbehavior. In this paper, we present a novel blockchain based approach to authenticate vehicles and notify other vehicles about any unauthorized messages in real time. This helps protect other vehicles in the network from making critical decisions based on false or inaccurate information. In the proposed architecture, vehicles communicate with each other using pseudonyms or pseudo IDs and the Blockchain is used to securely maintain the real identity of all vehicles, which can be linked to the pseudo IDs if needed. The goal is to protect privacy or individual vehicles, while still ensuring accountability in case of misbehavior. The performance of the proposed approach is evaluated for different vehicle and attacker densities, and results demonstrate it has lower authentication delay and communication overhead compared to existing approaches.
Huang, Liangqun, Xu, Lei, Zhu, Liehuang, Gai, Keke.  2021.  A Blockchain-Assisted Privacy-Preserving Cloud Computing Method with Multiple Keys. 2021 IEEE 6th International Conference on Smart Cloud (SmartCloud). :19–25.
How to analyze users' data without compromising individual privacy is an important issue in cloud computing. In order to protect privacy and enable the cloud to perform computing, users can apply homomorphic encryption schemes to their data. Most of existing homomorphic encryption-based cloud computing methods require that users' data are encrypted with the same key. While in practice, different users may prefer to use different keys. In this paper, we propose a privacy-preserving cloud computing method which adopts a double-trapdoor homomorphic encryption scheme to deal with the multi-key issue. The proposed method uses two cloud servers to analyze users' encrypted data. And we propose to use blockchain to monitor the information exchanged between the servers. Security analysis shows that the introduction of blockchain can help to prevent the two servers from colluding with each other, hence data privacy is further enhanced. And we conduct simulations to demonstrate the feasibility of the propose method.
Babrekar, Devika, Patel, Darsh, Patkar, Sachin, Lobo, Vivian Brian.  2021.  Blockchain-based Digital Locker using BigchainDB and InterPlanetary File System. 2021 6th International Conference on Communication and Electronics Systems (ICCES). :950–956.
Our identity as a human being is determined by the documents, not by appearance or physicality. The most important thing to prove the identity of humans is to show a government-issued document. Generally, from birth to death humans are recognized by documents because they are born with a birth certificate and they die with a death certificate. The main problem with these documents is that, they can be falsified or manipulated by others. Moreover in this digital era, they are stored in a centralized manner, which is prone to a cyber threat. This study aims to develop a blockchain environment to create, verify, and securely share documents in a decentralized manner. With the help of bigchainDB, interplanetary file system (IPFS), and asymmetric encryption, this research work will prototype the proposed solution called blockchain-based digital locker, which is similar to the DigiLocker released by the Department of Electronics and Information Technology (DeitY), Govt. of India. BigchainDB will help in treating each document as an asset by making it immutable with the help of IPFS and asymmetric encryption, where documents can not only be shared but also verified.
Baofu, Han, Hui, Li, Chuansi, Wei.  2021.  Blockchain-Based Distributed Data Integrity Auditing Scheme. 2021 IEEE 6th International Conference on Big Data Analytics (ICBDA). :143–149.
Cloud storage technology enables users to outsource local data to cloud service provider (CSP). In spite of its copious advantages, how to ensure the integrity of data has always been a significant issue. A variety of provable data possession (PDP) scheme have been proposed for cloud storage scenarios. However, the participation of centralized trusted third-party auditor (TPA) in most of the previous work has brought new security risks, because the TPA is prone to the single point of failure. Furthermore, the existing schemes do not consider the fair arbitration and lack an effective method to punish the malicious behavior. To address the above challenges, we propose a novel blockchain-based decentralized data integrity auditing scheme without the need for a centralized TPA. By using smart contract technique, our scheme supports automatic compensation mechanism. DO and CSP must first pay a certain amount of ether for the smart contract as deposit. The CSP gets the corresponding storage fee if the integrity auditing is passed. Otherwise, the CSP not only gets no fee but has to compensate DO whose data integrity is destroyed. Security analysis shows that the proposed scheme can resist a variety of attacks. Also, we implement our scheme on the platform of Ethereum to demonstrate the efficiency and effectiveness of our scheme.
Deng, Han, Fang, Fei, Chen, Juan, Zhang, Yazhen.  2021.  A Cloud Data Storage Technology for Alliance Blockchain Technology. 2021 7th IEEE Intl Conference on Big Data Security on Cloud (BigDataSecurity), IEEE Intl Conference on High Performance and Smart Computing, (HPSC) and IEEE Intl Conference on Intelligent Data and Security (IDS). :174–179.
The rapid development of blockchain application technology promotes continuous exploration in the field of computer application science. Although it is still in the initial stage of development, the technical features of blockchain technology such as decentralization, identity verification, tamper resistance, data integrity, and security are regarded as excellent solutions to today's computer security technical problems. In this paper, we will analyze and compare blockchain data storage and cloud data processing technologies, focusing on the concept and technology of blockchain distributed data storage technology, and analyze and summarize the key issues. The results of this paper will provide a useful reference for the application and research of blockchain technology in cloud storage security.
Cismas, Alexandru, Matei, Ioana, Popescu, Decebal.  2021.  Condensed Survey On Wearable IoBT Devices. 2021 International Conference on e-Health and Bioengineering (EHB). :1–4.
This document paper presents a critical and condensed analyze on series of devices that are intended for the military field, making an overview analysis of the technical solutions presented and that identifying those aspects that are really important for the military field or that offering a new approach. We currently have a wide range of medical devices that can be adapted for use in the military, but this adaptation must follow some well-defined aspects. A device that does not offer 100% reliability will be difficult to adopt in a military system, where mistakes are not allowed.
Breuer, Florian, Goyal, Vipul, Malavolta, Giulio.  2021.  Cryptocurrencies with Security Policies and Two-Factor Authentication. 2021 IEEE European Symposium on Security and Privacy (EuroS P). :140–158.
Blockchain-based cryptocurrencies offer an appealing alternative to Fiat currencies, due to their decentralized and borderless nature. However the decentralized settings make the authentication process more challenging: Standard cryptographic methods often rely on the ability of users to reliably store a (large) secret information. What happens if one user's key is lost or stolen? Blockchain systems lack of fallback mechanisms that allow one to recover from such an event, whereas the traditional banking system has developed and deploys quite effective solutions. In this work, we develop new cryptographic techniques to integrate security policies (developed in the traditional banking domain) in the blockchain settings. We propose a system where a smart contract is given the custody of the user's funds and has the ability to invoke a two-factor authentication (2FA) procedure in case of an exceptional event (e.g., a particularly large transaction or a key recovery request). To enable this, the owner of the account secret-shares the answers of some security questions among a committee of users. When the 2FA mechanism is triggered, the committee members can provide the smart contract with enough information to check whether an attempt was successful, and nothing more. We then design a protocol that securely and efficiently implements such a functionality: The protocol is round-optimal, is robust to the corruption of a subset of committee members, supports low-entropy secrets, and is concretely efficient. As a stepping stone towards the design of this protocol, we introduce a new threshold homomorphic encryption scheme for linear predicates from bilinear maps, which might be of independent interest. To substantiate the practicality of our approach, we implement the above protocol as a smart contract in Ethereum and show that it can be used today as an additional safeguard for suspicious transactions, at minimal added cost. We also implement a second scheme where the smart contract additionally requests a signature from a physical hardware token, whose verification key is registered upfront by the owner of the funds. We show how to integrate the widely used universal two-factor authentication (U2F) tokens in blockchain environments, thus enabling the deployment of our system with available hardware.
Lee, Taerim, Moon, Ho-Se, Jang, Juwook.  2021.  Data Encryption Method Using CP-ABE with Symmetric Key Algorithm in Blockchain Network. 2021 International Conference on Information and Communication Technology Convergence (ICTC). :1371–1373.
This paper proposes a method of encrypting data stored in the blockchain network by applying ciphertext-policy attribute-based encryption (CP-ABE) and symmetric key algorithm. This method protects the confidentiality and privacy of data that is not protected in blockchain networks, and stores data in a more efficient way than before. The proposed model has the same characteristics of CP-ABE and has a faster processing speed than when only CP-ABE is used.
Wu, Peiyan, Chen, Wenbin, Wu, Hualin, Qi, Ke, Liu, Miao.  2021.  Enhanced Game Theoretical Spectrum Sharing Method Based on Blockchain Consensus. 2021 IEEE 94th Vehicular Technology Conference (VTC2021-Fall). :1–7.
The limited spectrum resources need to provide safe and efficient spectrum service for the intensive users. Malicious spectrum work nodes will affect the normal operation of the entire system. Using the blockchain model, consensus algorithm Praft based on optimized Raft is to solve the consensus problem in Byzantine environment. Message digital signatures give the spectrum node some fault tolerance and tamper resistance. Spectrum sharing among spectrum nodes is carried out in combination with game theory. The existing game theoretical algorithm does not consider the influence of spectrum occupancy of primary users and cognitive users on primary users' utility and enthusiasm at the same time. We elicits a reinforcement factor and analyzes the effect of the reinforcement factor on strategy performance. This scheme optimizes the previous strategy so that the profits of spectrum nodes are improved and a good Nash equilibrium is shown, while Praft solves the Byzantine problem left by Raft.
Nair, P. Rajitha, Dorai, D. Ramya.  2021.  Evaluation of Performance and Security of Proof of Work and Proof of Stake using Blockchain. 2021 Third International Conference on Intelligent Communication Technologies and Virtual Mobile Networks (ICICV). :279–283.
Storing information in Blockchain has become in vogue in the Technical and Communication Industry with many major players jumping into the bandwagon. Two of the most prominent enablers for Blockchain are “Proof of Work” and “Proof of Stake”. Proof of work includes the members solving the complex problem without having a particular need for the solution (except as evidence, of course), which absorbs a large number of resources in turn. The proof of stake doesn’t require as many resources to enable Blockchain secure information store. Both methodologies have their advantages and their shortcomings. The article attempts to review the current literature and collate the results of the study to measure the performance of both the methodologies and to arrive at a consensus regarding either or both methodologies to implement Blockchain to store data. Post reviewing the performance aspects and security features of both Proofs of Stake and Proof of Work the reviewer attempts to arrive at a secure and better performing blended Blockchain methodology that has wide industry practical application.
Zhang, Zhaoqian, Zhang, Jianbiao, Yuan, Yilin, Li, Zheng.  2021.  An Expressive Fully Policy-Hidden Ciphertext Policy Attribute-Based Encryption Scheme with Credible Verification Based on Blockchain. IEEE Internet of Things Journal. :1–1.
As the public cloud becomes one of the leading ways in data sharing nowadays, data confidentiality and user privacy are increasingly critical. Partially policy-hidden ciphertext policy attribute-based encryption (CP-ABE) can effectively protect data confidentiality while reducing privacy leakage by hiding part of the access structure. However, it cannot satisfy the need of data sharing in the public cloud with complex users and large amounts of data, both in terms of less expressive access structures and limited granularity of policy hiding. Moreover, the verification of access right to shared data and correctness of decryption are ignored or conducted by an untrusted third party, and the prime-order groups are seldom considered in the expressive policy-hidden schemes. This paper proposes a fully policy-hidden CP-ABE scheme constructed on LSSS access structure and prime-order groups for public cloud data sharing. To help users decrypt, HVE with a ``convert step'' is applied, which is more compatible with CP-ABE. Meanwhile, decentralized credible verification of access right to shared data and correctness of decryption based on blockchain are also provided. We prove the security of our scheme rigorously and compare the scheme with others comprehensively. The results show that our scheme performs better.
Conference Name: IEEE Internet of Things Journal
Summerer, Christoph, Regnath, Emanuel, Ehm, Hans, Steinhorst, Sebastian.  2021.  Human-based Consensus for Trust Installation in Ontologies. 2021 IEEE International Conference on Blockchain and Cryptocurrency (ICBC). :1–3.
In this paper, we propose a novel protocol to represent the human factor on a blockchain environment. Our approach allows single or groups of humans to propose data in blocks which cannot be validated automatically but need human knowledge and collaboration to be validated. Only if human-based consensus on the correctness and trustworthiness of the data is reached, the new block is appended to the blockchain. This human approach significantly extends the possibilities of blockchain applications on data types apart from financial transaction data.
Zhang, Linlin, Ge, Yunhan.  2021.  Identity Authentication Based on Domestic Commercial Cryptography with Blockchain in the Heterogeneous Alliance Network. 2021 IEEE International Conference on Consumer Electronics and Computer Engineering (ICCECE). :191–195.
Aiming at ensure the security and self-control of heterogeneous alliance network, this paper proposes a novel structure of identity authentication based on domestic commercial cryptography with blockchain in the heterogeneous alliance network. The domestic commercial cryptography, such as SM2, SM3, SM4, SM9 and ZUC, is adopted to solve the encryption, decryption, signature and verification of blockchain, whose key steps of data layer are solved by using domestic commercial cryptographic algorithms. In addition, it is the distributed way to produce the public key and private key for the security of the keys. Therefore, the cross domain identity authentication in the heterogeneous alliance network can be executed safely and effectively.
Sun, Chuang, Shen, Sujin.  2021.  An Improved Byzantine Consensus Based Multi-Signature Algorithm. 2021 4th International Conference on Advanced Electronic Materials, Computers and Software Engineering (AEMCSE). :777–780.
Traditional grid-centric data storage methods are vulnerable to network attacks or failures due to downtime, causing problems such as data loss or tampering. The security of data storage can be effectively improved by establishing an alliance chain. However, the existing consortium chain consensus algorithm has low scalability, and the consensus time will explode as the number of nodes increases. This paper proposes an improved consensus algorithm (MSBFT) based on multi-signature to address this problem, which spreads data by establishing a system communication tree, reducing communication and network transmission costs, and improving system scalability. By generating schnorr multi-signature as the shared signature of system nodes, the computational cost of verification between nodes is reduced. At the end of the article, simulations prove the superiority of the proposed method.
Urien, Pascal.  2021.  Innovative Countermeasures to Defeat Cyber Attacks Against Blockchain Wallets. 2021 5th Cyber Security in Networking Conference (CSNet). :49–54.
Blockchain transactions are signed by private keys. Secure key storage and tamper resistant computing, are critical requirements for deployments of trusted infrastructure. In this paper we identify some threats against blockchain wallets, and we introduce a set of physical and logical countermeasures in order to defeat them. We introduce open software and hardware architectures based on secure elements, which enable detection of cloned device and corrupted software. These technologies are based on resistant computing (javacard), smartcard anti cloning, smartcard self content attestation, applicative firewall, bare metal architecture, remote attestation, dynamic PUF (Physical Unclonable Function), and programming token as root of trust.
Huang, Song, Yang, Zhen, Zheng, Changyou, Wan, Jinyong.  2021.  An Intellectual Property Data Access Control Method for Crowdsourced Testing System. 2021 8th International Conference on Dependable Systems and Their Applications (DSA). :434–438.
In the crowdsourced testing system, due to the openness of crowdsourced testing platform and other factors, the security of crowdsourced testing intellectual property cannot be effectively protected. We proposed an attribute-based double encryption scheme, combined with the blockchain technology, to achieve the data access control method of the code to be tested. It can meet the privacy protection and traceability of specific intellectual property in the crowdsourced testing environment. Through the experimental verification, the access control method is feasible, and the performance test is good, which can meet the normal business requirements.
Zheng, Siyuan, Yin, Changqing, Wu, Bin.  2021.  Keys as Secret Messages: Provably Secure and Efficiency-balanced Steganography on Blockchain. 2021 IEEE Intl Conf on Parallel Distributed Processing with Applications, Big Data Cloud Computing, Sustainable Computing Communications, Social Computing Networking (ISPA/BDCloud/SocialCom/SustainCom). :1269–1278.
To improve efficiency of stegosystem on blockchain and balance the time consumption of Encode and Decode operations, we propose a new blockchain-based steganography scheme, called Keys as Secret Messages (KASM), where a codebook of mappings between bitstrings and public keys can be pre-calculated by both sides with some secret parameters pre-negotiated before covert communication. By applying properties of elliptic curves and pseudorandom number generators, we realize key derivation of codebook item, and we construct the stegosystem with provable security under chosen hiddentext attack. By comparing KASM with Blockchain Covert Channel (BLOCCE) and testing on Bitcoin protocol, we conclude that our proposed stegosystem encodes hiddentexts faster than BLOCCE does and can decode stegotexts in highly acceptable time. The balanced time consumption of Encode and Decode operations of KASM make it applicable in the scene of duplex communication. At the same time, KASM does not leak sender’s private keys, so sender’s digital currencies can be protected.
Zhang, Hongao, Yang, Zhen, Yu, Haiyang.  2021.  Lightweight and Privacy-preserving Search over Encryption Blockchain. 2021 7th IEEE International Conference on Network Intelligence and Digital Content (IC-NIDC). :423—427.
With the development of cloud computing, a growing number of users use the cloud to store their sensitive data. To protect privacy, users often encrypt their data before outsourcing. Searchable Symmetric Encryption (SSE) enables users to retrieve their encrypted data. Most prior SSE schemes did not focus on malicious servers, and users could not confirm the correctness of the search results. Blockchain-based SSE schemes show the potential to solve this problem. However, the expensive nature of storage overhead on the blockchain presents an obstacle to the implementation of these schemes. In this paper, we propose a lightweight blockchain-based searchable symmetric encryption scheme that reduces the space cost in the scheme by improving the data structure of the encrypted index and ensuring efficient data retrieval. Experiment results demonstrate the practicability of our scheme.
Cherupally, Sumanth Reddy, Boga, Srinivas, Podili, Prashanth, Kataoka, Kotaro.  2021.  Lightweight and Scalable DAG based distributed ledger for verifying IoT data integrity. 2021 International Conference on Information Networking (ICOIN). :267—272.
Verifying the integrity of IoT data in cloud-based IoT architectures is crucial for building reliable IoT applications. Traditional data integrity verification methods rely on a Trusted Third Party (TTP) that has issues of risk and operational cost by centralization. Distributed Ledger Technology (DLT) has a high potential to verify IoT data integrity and overcome the problems with TTPs. However, the existing DLTs have low transaction throughput, high computational and storage overhead, and are unsuitable for IoT environments, where a massive scale of data is generated. Recently, Directed Acyclic Graph (DAG) based DLTs have been proposed to address the low transaction throughput of linear DLTs. However, the integration of IoT Gateways (GWs) into the peer to peer (P2P) DLT network is challenging because of their low storage and computational capacity. This paper proposes Lightweight and Scalable DAG based distributed ledger for IoT (LSDI) that can work with resource-constrained IoT GWs to provide fast and scalable IoT data integrity verification. LSDI uses two key techniques: Pruning and Clustering, to reduce 1) storage overhead in IoT GWs by removing sufficiently old transactions, and 2) computational overhead of IoT GWs by partitioning a large P2P network into smaller P2P networks. The evaluation results of the proof of concept implementation showed that the proposed LSDI system achieves high transaction throughput and scalability while efficiently managing storage and computation overhead of the IoT GWs.
Lin, Shanshan, Yin, Jie, Pei, Qingqi, Wang, Le, Wang, Zhangquan.  2021.  A Nested Incentive Scheme for Distributed File Sharing Systems. 2021 IEEE International Conference on Smart Internet of Things (SmartIoT). :60—65.
In the distributed file sharing system, a large number of users share bandwidth, upload resources and store them in a decentralized manner, thus offering both an abundant supply of high-quality resources and high-speed download. However, some users only enjoy the convenient service without uploading or sharing, which is called free riding. Free-riding may discourage other honest users. When free-riding users mount to a certain number, the platform may fail to work. The current available incentive mechanisms, such as reciprocal incentive mechanisms and reputation-based incentive mechanisms, which suffer simple incentive models, inability to achieve incentive circulation and dependence on a third-party trusted agency, are unable to completely solve the free-riding problem.In this paper we build a blockchain-based distributed file sharing platform and design a nested incentive scheme for this platform. The proposed nested incentive mechanism achieves the circulation of incentives in the platform and does not rely on any trusted third parties for incentive distribution, thus providing a better solution to free-riding. Our distributed file sharing platform prototype is built on the current mainstream blockchain. Nested incentive scheme experiments on this platform verify the effectiveness and superiority of our incentive scheme in solving the free-riding problem compared to other schemes.
Badra, Mohamad, Borghol, Rouba.  2021.  Privacy-Preserving and Efficient Aggregation for Smart Grid based on Blockchain. 2021 11th IFIP International Conference on New Technologies, Mobility and Security (NTMS). :1—3.
In this paper, we address the problem of privacy-preserving of the consumer's energy measurements in the context of the SG. To this end, we present a blockchain-based approach to preserve the privacy for smart grid users and to detect data forgery, replay attacks, and data injection attacks.