Electronic voting (e-voting) presents a convenient and cost-effective alternative to current paper ballot-based voting. It provides many benefits such as increased voter turnout and accuracy in the decision-making process. While presenting many improvements, e-voting still faces serious security challenges that hinder its adoption, especially when designed to be run over mobile devices. In this article, we propose a novel remote e-voting model for large-scale elections by proposing the participation of two conflicting parties to ensure election integrity and accountability. Our scheme can be implemented in IoT devices such as smartphones, which we believe can significantly increase voter turnout of the election process. Our proposed work is secure and preserves voter privacy through secure multiparty computations performed by parties of differing allegiances. It also leverages a blockchain running smart contracts as a publicly accessible and tamper-resistant bulletin board to permanently store votes and prevent double voting. In our security and privacy analysis, we show that our proposed scheme is secure against potential security threats and provides voter anonymity. We show orthogonality between universal verifiability and coercion resistance in our proposed scheme, allowing an election to favor one over the other. Our performance analysis and smartphone simulation results show that the proposed scheme is practical for large-scale elections.
Online auction systems allow to achieve an optimal trading of digital goods and services in a competitive market. Existing blockchain-based auctions allow the bidders to take part in the process while maintaining the confidentiality of their bids in a decentralized, transparent, secure and auditable way. However, in a competitive market, parties would prefer not to disclose their interests to competitors, and to remain anonymous during auctions. In this paper, we firstly analyze the specific requirements for blockchain-based anonymous fair auctions. We propose a formal model tailored to study auction systems facilitating anonymity, and we put forward a generic protocol relying on existing cryptographic primitives, such as designated verifier ring signature, to achieve bid confidentiality and bidder anonymity. Finally, we prove it to be secure against the security model we defined.
Open access
Blockchain Technology Applications and Security
Internet Traffic Analysis and Secure E-voting
Advanced Steganography and Watermarking Techniques
Xi He, Ketai He, Shenwen Lin, Jinglin Yang · 5 authors
Abstract Single heuristic method and incomplete heuristic conditions were difficult to cluster a large number of addresses comprehensively and accurately. Therefore, this paper analysed the associations between Bitcoin transactions and addresses and used six heuristic conditions to cluster addresses and entities. We proposed an improved change address detection algorithm and compared it with the original change address algorithm to prove the effectiveness of the improved algorithm. By adding conditional constraints, the identified change address was more accurate, and the convergence speed of the algorithm was accelerated. Our work presented the pseudo‐anonymity mechanism of the Bitcoin system, which could be used by the law enforcement agencies to track and crack down illegal transactions.
Jun Huang, Debiao He, Mohammad S. Obaidat, Pandi Vijayakumar · 6 authors
Voting is a formal expression of opinion or choice, either positive or negative, made by an individual or a group of individuals. However, conventional voting systems tend to be centralized, which are known to suffer from security and efficiency limitations. Hence, there has been a trend of moving to decentralized voting systems, such as those based on blockchain. The latter is a decentralized digital ledger in a peer-to-peer network, where a copy of the append-only ledger of digitally signed and encrypted transactions is maintained by each participant. Therefore, in this article, we perform a comprehensive review of blockchain-based voting systems and classify them based on a number of features (e.g., the types of blockchain used, the consensus approaches used, and the scale of participants). By systematically analyzing and comparing the different blockchain-based voting systems, we also identify a number of limitations and research opportunities. Hopefully, this survey will provide an in-depth insight into the potential utility of blockchain in voting systems and device future research agenda.
Matthew Tsao, Kaidi Yang, Stephen Zoepf, Marco Pavone
The era of big data has brought with it a richer understanding of user behavior through massive datasets, which can help organizations optimize the quality of their services. In the context of transportation research, mobility data can provide municipal authorities (MAs) with insights on how to operate, regulate, or improve the transportation network. Mobility data, however, may contain sensitive information about end users and trade secrets of mobility providers (MPs). Due to this data privacy concern, MPs may be reluctant to contribute their datasets to MA. Using ideas from cryptography, we propose an interactive protocol between an MA and an MP, in which MA obtains insights from mobility data without MP having to reveal its trade secrets or sensitive data of its users. This is accomplished in two steps: 1) a commitment step and 2) a computation step. In the first step, Merkle commitments and aggregated traffic measurements are used to generate a cryptographic commitment. In the second step, MP extracts insights from the data and sends them to MA. Using the commitment and zero-knowledge proofs, MA can certify that the information received from MP is accurate, without needing to directly inspect the mobility data. We also present a differentially private version of the protocol that is suitable for the large query regime. The protocol is verifiable for both MA and MP in the sense that dishonesty from one party can be detected by the other. The protocol can be readily extended to the more general setting with multiple MPs via secure multiparty computation.
This PhD thesis focuses on lattice-based cryptography and how to apply it to build post-quantum online voting systems. It is the result of the research done by the author at Scytl in close collaboration with Dr. Paz Morillo, from the Department of Applied Mathematics at UPC and Ramiro Martínez, PhD student. As part of her work at the electronic voting company Scytl, the author has participated in the design of several electronic voting systems as well as in their implementation, by providing support to the development team. Nevertheless, all these systems use standard and well-known cryptographic primitives, i.e., not lattice-based primitives, to ensure that the security requirements are fulfilled. Due to this, one of the main challenges of this PhD has been to start researching on a field which was not familiar to the author and contribute to its state of the art. This has allowed the company to enter the post-quantum world by participating in a project which aims to implement a lattice-based online voting system. The thesis has the following contents: an introduction to the lattice theory by describing some of its basic concepts and the computational problems in which the security of lattice-based cryptosystems relies. In this first part it is also described in detail those cryptosystems that are used as building blocks of three new protocols proposed in the thesis: a lattice-based coercion-resistant cast-as-intended protocol, a post-quantum mix-net and a fully post-quantum proof of a shuffle. The former is the lattice version of an existing protocol and allows the voter to check that the vote cast contains the selected voting options. The second and third protocols are the result of the research on lattice-based mix-nets. Two constructions are proposed: the first one allows to demonstrate that a mix-node has permuted and re-encrypted a list of RLWE ciphertexts without modifying them, but it cannot be considered fully post-quantum since the binding property of the commitment scheme relies on classical computational problems. The second one is fully post-quantum since all the cryptographic schemes used for building it, i.e., commitment scheme and zero-knowledge proofs, are based on lattices. Last but not least, for this second proposal a security definition and a proof of security are also provided. Finally, the last part of the thesis consists of building a post-quantum online voting system using as building blocks the protocols already presented and existing lattice-based constructions. This system is considered secure under quantum attacks and provides long-term privacy. It also guarantees vote anonymity, vote authenticity, vote integrity, individual verifiability and receipt-freeness. The algorithms involved in each phase are described in detail as well as the interaction among the participants. An implementation of this system is not given as part of this thesis although a lattice-based online voting system based on that is already being implemented at the company. Aquest tesi es centra en la criptografia basada en reticles i com aplicar-la a la construcció de sistemes de votació electrònica post-quàntics. És el fruit de la recerca feta per l'autora de la tesi a Scytl en estreta col·laboració amb la Dra. Paz Morillo, del Departament de Matemàtica Aplicada de la UPC i en Ramiro Martínez, estudiant de doctorat. Com a part de la seva feina a l'empresa de vot electrònic Scytl, l'autora ha participat tant en el disseny de sistemes de votació electrònica com en la seva implementació, donant suport a l'equip de desenvolupament. No obstant, tots aquests sistemes utilitzen primitives criptogràfiques estàndard (primitives no basades en reticles) per assegurar que els requisits de seguretat es compleixen, i és per aquest motiu que un dels principals reptes d'aquest doctorat ha estat fer en recerca en un camp que no era familiar per l'autora, i contribuir-hi. Per altra banda, això ha permès a l'empresa endinsar-se en el món post-quàntic i participar en un projecte que té per objectiu implementar un sistema de vot electrònic basat en reticles. Aquest tesi consta dels següents continguts: una introducció a la teoria dels reticles on es descriuen alguns dels seus conceptes bàsics i els problemes computacionals dels quals depèn la seguretat dels criptosistemes basats en reticles. En aquesta primera part també es descriuen en detall aquells criptosistemes utilitzats en la construcció dels tres nous protocols presentats en aquesta tesi: un protocol basat en reticles resistent a la coacció i que ofereix verificabilitat “cast-as-intended”; una “mix-net post-quàntica” i una prova de coneixement nul totalment post-quàntica que permet demostrar que la barreja de vots s'ha realitzat correctament. El primer protocol és la versió basada en reticles d'un protocol ja existent i permet que el votant comprovi que el vot emès conté les opcions que havia seleccionat. El segon i el tercer protocol són el resultat de la recerca feta en el camp de les mix-nets basades en reticles. Es proposen dues construccions: la primera d'elles permet demostrar que un node de la mix-net ha barrejat i rexifrat una llista de xifrats RLWE sense modificar-los, però no es pot considerar totalment post-quàntica ja que la propietat de lligar de l'esquema de compromís utilitzat per construir la prova es basa en problemes computacionals clàssics. La segona construcció és totalment post-quàntica ja que tots els esquemes criptogràfics utilitzats en el seu disseny, és a dir, esquema de compromís i proves de coneixement nul, estan basats en reticles. Finalment, però no per això menys important, per aquesta segona proposta també es dóna una definició de seguretat i una prova de seguretat. L'última part de la tesi consisteix en construir un sistema de vot online post-quàntic, utilitzant com a components els protocols prèviament presentats i construccions ja existents basades en reticles. El sistema es considera segur en front atacs quàntics i ofereix privadesa a llarg plaç. També garanteix l'anonimat del vot, la seva autenticitat i integritat, verificabilitat individual i resistència a la coacció. Es descriuen en detall tant els algoritmes executats a cada fase com la interacció entre els seus participants. Com a part de la tesi no s'inclou cap implementació del sistema tot i que l'empresa està implementant un sistema de vot online basat en el que es presenta en aquesta tesi.
Mohammed Amine Bouras, Boming Xia, Adnan Omer Abuassba, Huansheng Ning · 5 authors
Access control is a critical aspect for improving the privacy and security of IoT systems. A consortium is a public or private association or a group of two or more institutes, businesses, and companies that collaborate to achieve common goals or form a resource pool to enable the sharing economy aspect. However, most access control methods are based on centralized solutions, which may lead to problems like data leakage and single-point failure. Blockchain technology has its intrinsic feature of distribution, which can be used to tackle the centralized problem of traditional access control schemes. Nevertheless, blockchain itself comes with certain limitations like the lack of scalability and poor performance. To bridge the gap of these problems, here we present a decentralized capability-based access control architecture designed for IoT consortium networks named IoT-CCAC. A blockchain-based database is utilized in our solution for better performance since it exhibits favorable features of both blockchain and conventional databases. The performance of IoT-CCAC is evaluated to demonstrate the superiority of our proposed architecture. IoT-CCAC is a secure, salable, effective solution that meets the enterprise and business's needs and adaptable for different IoT interoperability scenarios.
Chiara Spadafora, Riccardo Longo, Massimiliano Sala
We propose a decentralized e-voting protocol that is coercion-resistant and vote-selling resistant, while being also completely transparent and not receipt-free. We achieve decentralization using blockchain technology. Because of the properties such as transparency, decentralization, and non-repudiation, blockchain is a fundamental technology of great interest in its own right, and it also has large potential when integrated into many other areas. We prove the security of the protocol under the standard DDH assumption on the underlying prime-order cyclic group (e.g. the group of points of an elliptic curve), as well as under standard assumptions on blockchain robustness.
The Blockchain is one of the recent technologies that have emerged in the last decade. Blockchain has become a topic of many researches in several fields and it was implemented in some industries like finance, energy, health care, and electronic voting. Blockchain presents some great potential solutions that help to tackle difficulties. In this work we will focus on e-voting using blockchain technology. As we all know the voting is a way that leads the governments to approach democracy in their countries by an electoral process. The blockchain voting has replaced the traditional vote paper, also it replaced the voting systems that store data in central database. That gave much efficiency to the blockchain technology through a decentralized system that requires anonymity, confidentiality and transparency.
Bitcoin came into existence as a peer-to-peer payment system for use on online transactions. This achievement was the result of a shared vision about the future relationship between governments’ control and citizenry, and the collaborative work of the many who contributed to the development of the cryptographic field. This innovation and its underlying technology, the blockchain, have been at the root of a change of paradigm, as the joint use of blockchain and artificial intelligence (AI) seed the next technological revolution. However, as it is often the case, these revolutionary inventions have also been met with skepticism in the financial sector and society at large. Using the case of Bitcoin and the blockchain, this paper analyzes the intersection between the philosophy and technology underlying these innovations, and the outlook of a sector of society who fears these developments while others try to profit. In this chapter, we first look at the history of Bitcoin together with that of those behind it. We then review the mixed reception it obtained after coming to the market. We assess the innovations’ properties and confront these with the needs of a society eager to obtain further clarity and enjoy more transparency in matters of relevance to their participation in democratic processes.
As an innovative type of decentralized model, blockchain is a growing list of blocks linked by cryptography. Blockchain incorporates anonymity protocol, distributed data storage, consensus algorithm, and smart contract. The anonymity protocols in blockchain are significant in that they could protect users from leaking their personal information. In this paper, we will conduct a detailed review and comparison of anonymity protocols used in three famous cryptocurrencies, namely Bitcoin, Zcash, and Ethereum.
Blockchain Technology Applications and Security
Advanced Steganography and Watermarking Techniques
The Domain Name System (DNS) plays a crucial role in the Internet. However, it is vulnerable to many attacks such as the cache poisoning attack and DDoS attack. Though some countermeasures have been proposed, they still have some limitations. In this paper, we propose B-DNS, a blockchain-based domain name system, which can provide a secure and efficient DNS service. B-DNS fills up two shortcomings of current blockchain-based DNS, namely computation-heavy Proof-of-Work (PoW) protocol and inefficient query, by building a Proof-of-Stake (PoS) consensus protocol and an index of domains. We propose a novel way to quantitatively compare the security of B-DNS and legacy DNS in terms of attack success rate, attack cost, and attack surface. Our experiments show that the probability of a successful attack on B-DNS is 1% of a successful attack on legacy DNS, the attack cost goes up a million times in B-DNS, and the attack surface of B-DNS is far smaller than that of legacy DNS. The query performance evaluation of B-DNS shows that B-DNS can achieve similar or even less query latency than state-of-the-art commercial DNS implementations.
Stefano Bistarelli, Ivan Mercanti, Francesco Faloci, Francesco Santini
We highlight how Bitcoin addresses are reused in transactions (implicitly or explicitly), despite recommendations and best practice strongly advise to avoid this. We analyse the blockchain with the purpose to find and count highly reused Bitcoin addresses, starting from the birth of the protocol in 2009. In this study we also include hidden addresses: these addresses are not the explicit endpoints of a transaction, but they are somehow contained in it (e.g., in the script of a Pay to Script Hash transaction). Finally, we try to de-anonymise the top-100 reused addresses, grouping and linking them to their wallet owner. This work shows that such a misuse in reusing the address often corresponds to malicious activities in the bitcoin ecosystem. These results push towards a mandatory single usage, which mitigates dangerous consequences.
Voting is one of the most fundamental aspects of democracy. Over the past few decades, voting methods around the world have expanded from traditional paper ballot systems to electronic voting (e-voting), in which votes are written directly to computer memory. Like any computer system, voting machines are susceptible to technical vulnerabilities that open up opportunities for hackers to tamper with votes, causing the use of electronic voting technology to raise concerns about ballot security. We describe how electronic voting can be supported by blockchain technology to ensure voter secrecy, vote correctness, and equal voting rights. In this paper, we present a system using two separate blockchains, each with separate transactions and consensus algorithms. We describe a prototype implementation that validates our ideas by executing several proof-of-concept simulations of a range of voting scenarios.
Structuring an electronic voting system which fulfills the legitimate requirements of representatives has been a challenge for a long time. Conducting the free, systematic and impartial election is the vital goal of every democracy nation. Every country follows a different voting system from old paper ballot system to Electronic voting system. There facing a many problem in these voting systems. The main problem is location and the accessibility, people are suffering to go to their native place polling booth for casting their vote. This needs to be considered as every people`s vote plays significant role in deciding the right leaders. Blockchain technology offers the transparency and security requisites for the impartial election. It is a complete decentralized, immutable ledger system. The online voting system allows the voters to cast their vote from any place at any time which leads to increasing the voter participation count. The objective of the paper is to create a voting system which provides transparency and security using Blockchain technology, the Ganache tool is used for setting up a local blockchain network. The metamask is used for account verification.
Blockchain Technology Applications and Security
Internet Traffic Analysis and Secure E-voting
Advanced Steganography and Watermarking Techniques
The traditional covert communication channel relying on a third-party node is vulnerable to attack. The data are easily tampered with and the identity information of the communication party is fragile. Blockchain has the characteristics of decentralization and tamper resistance, which can effectively solve the above problems. In addition, some confidential information needs to be transmitted covertly in the transparent blockchain. A smart contract deployed in the blockchain to automatically realize its function can replace a centralized node to provide credible guarantee for communication. The diversity of parameters, data redundancy, and code programmability of smart contract make it an excellent carrier for covert communication under blockchain. In this article, we propose a covert communication model combined with smart contracts to covertly transfer information in the blockchain environment. To implement this model, we use the parameters in the contract to map the secret information sequence, and call the contract to transfer message. Voting contract and secret bidding contract are combined to instantiate the proposed model, and optimized versions of the two contracts are also proposed to reduce costs. Moreover, we use encryption algorithms and two-round protocols to ensure data privacy and design corresponding information embedding and transmission methods for different scenarios. To improve the concealment of communication, redundant options, effective price ranges, and invalid bids are set in two contracts, respectively. The experimental results show that the proposed model has tamper resistance and low complexity, and it is feasible to use this model for covert communication.
Intrusion Detection System (IDS) is one of the most important approaches in cyber security to protect networks against both inner and outer threats. Apart from traditional networks, IDSs have been implemented in various emerging networks, such as mobile networks and Vehicle Ad hoc Networks (VANETs). However, a critical problem in IDSs is that the detection capacity is gradually decaying with the emergence of unknown attacks. It is necessary to constantly retrain IDSs with a more extensive database, but the security institutes usually lack the motivation to persistently update and maintain the database for public. Thus, in this paper, a lifetime learning framework is proposed for IDSs with a blockchain-based database (bc-DB). In the proposed framework, the blockchain-based database is multilaterally maintained by the security institutes and universities using Data Coins (DCoins) as the incentives. In addition, a Lifetime Learning IDS (LL-IDS) is further designed as the supplement of the bc-DB for common IDS users. For the LL-IDS, the Growing Hierarchical Self-Organizing Map with probabilistic relabeling (GHSOM-pr) having flexible and hierarchical architecture is employed as the classifier, which grows to make itself perfectly fit the changeable bc-DB. Security analysis and simulation experiments show that the proposed lifetime learning framework are both secure and effective in attacks detection.
R Manikandaprabhu, Mohamed Ashwak M., Mohamed Ashwak P, K Jegan · 5 authors
An electoral system or voting system is a set of rules that determine how elections and referendums are conducted and how their results are determined. Election is a very important event in a modern democracy but large sections of society around the world do not trust their election system which is major concern for the democracy. Distributed ledger technology is an exciting technological advancement in the information technology world. Blockchain Technologies offer an infinite range of applications benefiting from sharing economies. In this paper the proposed system is to store the ballot information as a block node for each and every voter and transfer the voters vote hash over the internet to all other nodes. The proposed system is cost-efficient when compared to the traditional electronic voting machines.