Electronic voting (e-voting) is an electronic means for casting and counting votes. It is an efficient and cost-effective way for conducting a voting procedure, which has characteristic of being magnanimous data and real time and requesting high safety. However, concerns on security of networking and privacy of communication for e-voting have been grown. Securing e-voting is very urgent and has becoming a popular topic in the area of communications and networking. We present techniques to exploit blockchain in P2P network to improve the security of e-voting. First, we design a synchronized model of voting records based on distributed ledger technology (DLT) to avoid forgery of votes. Second, we design a user credential model based on elliptic curve cryptography (ECC) to provide authentication and non-repudiation. Third, we design a withdrawal model that allows voters to change their vote before a preset deadline. By integrating the above designs, a blockchain-based e-voting scheme in P2P network is proposed for essential requirements of e-voting process. To prove and verify the scheme, a blockchain-based e-voting system for multiple candidates has been designed on Linux platforms in P2P network. The system involves electronic voting theory, cryptography, and software engineering theory. The implementation result shows that it is a practical and secure e-voting system, which solves the problem on forgery of votes during e-voting. The blockchain-based e-voting system can be applied to a variety of networking applications directly.
Open access
Internet Traffic Analysis and Secure E-voting
Advanced Steganography and Watermarking Techniques
Zero-Knowledge Proof-of-Identity from trusted public certificates (e.g.,\nnational identity cards and/or ePassports; eSIM) is introduced here to\npermissionless blockchains in order to remove the inefficiencies of\nSybil-resistant mechanisms such as Proof-of-Work (i.e., high energy and\nenvironmental costs) and Proof-of-Stake (i.e., capital hoarding and lower\ntransaction volume). The proposed solution effectively limits the number of\nmining nodes a single individual would be able to run while keeping membership\nopen to everyone, circumventing the impossibility of full decentralization and\nthe blockchain scalability trilemma when instantiated on a blockchain with a\nconsensus protocol based on the cryptographic random selection of nodes.\nResistance to collusion is also considered.\n Solving one of the most pressing problems in blockchains, a zk-PoI\ncryptocurrency is proved to have the following advantageous properties:\n - an incentive-compatible protocol for the issuing of cryptocurrency rewards\nbased on a unique Nash equilibrium\n - strict domination of mining over all other PoW/PoS cryptocurrencies, thus\nthe zk-PoI cryptocurrency becoming the preferred choice by miners is proved to\nbe a Nash equilibrium and the Evolutionarily Stable Strategy\n - PoW/PoS cryptocurrencies are condemned to pay the Price of Crypto-Anarchy,\nredeemed by the optimal efficiency of zk-PoI as it implements the social\noptimum\n - the circulation of a zk-PoI cryptocurrency Pareto dominates other PoW/PoS\ncryptocurrencies\n - the network effects arising from the social networks inherent to national\nidentity cards and ePassports dominate PoW/PoS cryptocurrencies\n - the lower costs of its infrastructure imply the existence of a unique\nequilibrium where it dominates other forms of payment\n
Lyra2REv2 is a hashing algorithm that consists of a chain of individual hashing algorithms, and it is used as a proof-of-work function in several cryptocurrencies. The most crucial and exotic hashing algorithm in the Lyra2REv2 chain is a specific instance of the general Lyra2 algorithm. In this work, we present the first hardware implementation of the specific instance of Lyra2 that is used in Lyra2REv2 and we explain how several properties of this algorithm can be exploited in order to optimize the design. Moreover, we present an FPGA-based hardware implementation of a full miner chain for Lyra2REv2 on a Xilinx Multi-Processor System on Chip. Our proposed Lyra2REv2 miner chain is shown to be significantly more energy efficient than both a GPU and a commercially available FPGA-based miner. Finally, we also explain how our simplified Lyra2 and Lyra2REv2 architectures can be modified with minimal effort to also support the recent Lyra2REv3 chained hashing algorithm.
Muriel Figueredo Franco, Eder J. Scheid, Lisandro Zambenedetti Granville, Burkhard Stiller
Network Functions Virtualization (NFV) is transforming the way in which network operators acquire and manage network services. By using virtualization technologies to move packet processing from dedicated hardware to software, NFV has introduced a new market focused on the offer and distribution of Virtual Network Functions (VNF). Infrastructure Providers (InP) can benefit from an NFV market by providing their infrastructures to fulfill demands of end-users that, in turn, acquire VNFsas- a-Service (VNFaaS). In this context, solutions that promote the competition between InPs can lead to lower prices, while increasing VNF performance to accommodate specific demands of end-users. In this paper, BRAIN, a blockchain-based reverse auction is presented to introduce an auditable solution in which InPs can compete to host VNFs taking into account the demands of each particular end-user. Such a solution helps reduce costs involved in VNF's commercialization and also monetize NFVenabled infrastructures. BRAIN is supported by a case study that provides evidence of the solution's feasibility and effectiveness. A discussion regarding blockchain advantages and drawbacks in this use-case (e.g., , additional costs and time) concludes this paper.
Amin Kharraz, Zane Ma, Paul Murley, Charles Lever · 9 authors
In-browser cryptojacking is a form of resource abuse that leverages end-users' machines to mine cryptocurrency without obtaining the users' consent. In this paper, we design, implement, and evaluate Outguard, an automated cryptojacking detection system. We construct a large ground-truth dataset, extract several features using an instrumented web browser, and ultimately select seven distinctive features that are used to build an SVM classification model. Outguardachieves a 97.9% TPR and 1.1% FPR and is reasonably tolerant to adversarial evasions. We utilized Outguardin the wild by deploying it across the Alexa Top 1M websites and found 6,302 cryptojacking sites, of which 3,600 are new detections that were absent from the training data. These cryptojacking sites paint a broad picture of the cryptojacking ecosystem, with particular emphasis on the prevalence of cryptojacking websites and the shared infrastructure that provides clues to the operators behind the cryptojacking phenomenon.
Ethereum is an open-source, public, blockchain-based distributed computing platform and operating system featuring smart contract functionality. In this paper, we proposed an Ethereum based eletronic voting (e-voting) protocol, Ques-Chain, which can ensure the authentication can be done without hurting confidentiality and the anonymity can be protected without problems of scams at the same time. Furthermore, the authors considered the wider usages Ques-Chain can be applied on, pointing out that it is able to process all kinds of messages and can be used in all fields with similar needs.
Reza M. Parizi, Sajad Homayoun, Abbas Yazdinejad, Ali Dehghantanha · 5 authors
Blockchains are turning into decentralized computing platforms and are getting worldwide recognition for their unique advantages. There is an emerging trend beyond payments that blockchains could enable a new breed of decentralized applications, and serve as the foundation for Internet's security infrastructure. The immutable nature of the blockchain makes it a winner on security and transparency; it is nearly inconceivable for ledgers to be altered in a way not instantly clear to every single user involved. However, most blockchains fall short in privacy aspects, particularly in data protection. Garlic Routing and Onion Routing are two of major Privacy Enhancing Techniques (PETs) which are popular for anonymization and security. Garlic Routing is a methodology using by I2P Anonymous Network to hide the identity of sender and receiver of data packets by bundling multiple messages into a layered encryption structure. The Onion Routing attempts to provide low-latency Internet-based connections that resist traffic analysis, deanonymization attack, eavesdropping, and other attacks both by outsiders (e.g. Internet routers) and insiders (Onion Routing servers themselves). As there are a few controversies over the rate of resistance of these two techniques to privacy attacks, we propose a PET-Enabled Sidechain (PETES) as a new privacy enhancing technique by integrating Garlic Routing and Onion Routing into a Garlic Onion Routing (GOR) framework suitable to the structure of blockchains. The preliminary proposed GOR aims to improve the privacy of transactions in blockchains via PETES structure.
Liang Wang, Gilad Asharov, Rafael Pass, Thomas Ristenpart · 5 authors
We explore how to build a blind certificate authority (CA). Unlike conventional CAs, which learn the exact identity of those registering a public key, a blind CA can simultaneously validate an identity and provide a certificate binding a public key to it, without ever learning the identity. Blind CAs would therefore allow bootstrapping truly anonymous systems in which no party ever learns who participates. In this work we focus on constructing blind CAs that can bind an email address to a public key. To do so, we first introduce secure channel injection (SCI) protocols. These allow one party (in our setting, the blind CA) to insert a private message into another party's encrypted communications. We construct an efficient SCI protocol for communications delivered over TLS, and use it to realize anonymous proofs of account ownership for SMTP servers. Combined with a zero-knowledge certificate signing protocol, we build the first blind CA that allows Alice to obtain a X.509 certificate binding her email address alice@domain.com to a public key of her choosing without ever revealing ``alice'' to the CA. We show experimentally that our system works with standard email server implementations as well as Gmail.
The Blockchain-Enabled E-Voting uses a digital-currency analogy where in eligible voters can cast a ballot anonymously using a computing environment. BEV employs an encrypted key, smart biometrics and tamperproof realtime personal ID verification. Blockchain enable the creation of tamper-proof audit trails for voting. The idea of adapting digital voting systems to make the public electoral process cheaper, faster and easier, is a compelling one in modern society which normalizes it in the eyes of the voters, removes a certain power barrier between the voter and the elected candidate, thus making it an effective way for casting vote in this generation of technology.
Traditional voting and bidding systems largely rely on paperwork and human resources throughout the voting process, which can incur high costs in terms of both time and money. Electronic voting and electronic bidding systems can be used to reduce costs, and many new systems have been introduced. However, most systems require a powerful and trusted third party to guarantee system integrity and security. With developments in blockchain technology, research has begun to highlight the core concept of decentralization. In this study, we introduce the first decentralized electronic voting and bidding systems based on a blockchain and smart contract. We also use cryptographic techniques such as oblivious transfer and homomorphic encryptions to improve privacy protection. Our proposed systems allow voters and bidders to participate in the opening phase and improve participant anonymity, the privacy of data transmission, and data reliability and verifiability. Moreover, compared with other electronic voting and bidding systems, our systems are safer and more efficient.
Bruno Rodrigues, Lukas Eisenring, Eder J. Scheid, Thomas Bocek · 5 authors
The volume of traffic generated by modern Distributed Denial-of-Service (DDoS) attacks suggests that centralized defenses are not the most effective approach to counter these attacks. An alternative to reduce the burden of detection and mitigation is to combine centralized defense systems, creating a global and cooperative protection system. However, existing approaches suffer from the complexity of deployment and operation across different systems. Blockchains appear in this scenario as an alternative to simplify the exchange of information in a cooperative defense. This work evaluates in both local and global experimentations the performance of the blockchain system proposed in [8] concerning the latency to perform the signaling of blacklisted addresses.
Abrar O. Alkhamisi and Fathy Alboraei Abrar O. Alkhamisi and Fathy Alboraei
In recent years, the Internet of Things (IoT) plays a vital role in our daily activities .Owing to the increased number of vulnerabilities on the IoT devices, security becomes critical in the untrustworthy IoT environment. Access control is one of the top security concerns, however, implementing the traditional access control mechanisms in the resource-constrained nature of the IoT devices is a challenging task. With the emergence of blockchain technology, several recent research works have focused on the adoption of blockchain in IoT to resolve the security concerns. Despite, integrating the blockchain in the resource-constrained IoT context is difficult. To overcome these obstacles, the proposed work presents a privacy-aware IoT security architecture to ensure the access control based on Smart contract for resource-constrained and distributed IoT devices. The design of the proposed architecture incorporates three main components such as the contextual blockchain gateway, decentralized revocation manager, and non-interactive zero-knowledge proof based validation. By modeling the contextual blockchain gateway, the proposed architecture ensures the dynamic authentication and authorization based on the contextual information and access policies. Instead of integrating the blockchain technology into resource-constrained IoT devices, the smart contract-based distributed access control system with the contextual blockchain gateway provides the scalable solution. With the association of decentralized revocation manager in the smart contract, it prevents the resource access from the unauthorized users by dynamically generating and updating the revoked user list of all the nodes in the smart contract. Moreover, the proposed architecture employs the non-interactive zeroknowledge proof cryptographic protocol to ensure the transaction privacy within the smart contract. Consequently, it maintains the trade-off between the transparency and privacy while ensuring the security for the distributed IoT environment.
Bitcoin is a decentralized digital currency introduced in 2008 and launched in 2009. Bitcoin provides a way to transact without any trusted intermediary, but its privacy guarantees are questionable, and multiple deanonymization attacks have been proposed. Cryptocurrency privacy research has been mostly focused on blockchain analysis, i.e., extracting information from the transaction graph. We focus on another vector for privacy attacks: network analysis. We describe the message propagation mechanics in Bitcoin and propose a novel technique for transaction clustering based on network traffic analysis. We show that timings of transaction messages leak information about their origin, which can be exploited by a well connected adversarial node. We implement and evaluate our method in the Bitcoin testnet with a high level of accuracy, deanonymizing our own transactions issued from a desktop wallet (Bitcoin Core) and from a mobile (Mycelium) wallet. Compared to existing approaches, we leverage the propagation information from multiple peers, which allows us to overcome an anti-deanonymization technique (“diffusion”) used in Bitcoin.
Blockchain teknolojisi, resmi kurumların katkısı olmadan bir ağa bağlı bilgisayarlar aracılığı ile çeşitli onaylama ve doğrulama işlemlerinin gerçekleştirildiği bir sistemdir. 21. yy’da ortaya çıkan blockchain teknolojisi ve kripto paraların hızla yatırım aracına dönüştüğü görülmektedir. Bu çalışmada blockchain teknolojisinin kullanımı sonucu ortaya çıkan kripto paralar, paranın tarihinden yola çıkılarak incelenmeye çalışılmıştır. Kripto paralar sahip olduğu gücü insanların güveninden alırken, geleneksel para gücünü kendisini piyasaya süren devletten almaktadır. Bu çalışmada kripto paraların güçlü ve zayıf yönleri anlatılarak gelecekte geleneksel para birimi gibi kullanılıp kullanılamayacağı incelenmiştir. Kripto paraların bir para birimi olmaktan çok bir yatırım aracı olarak kullanıldığı görülmektedir. İnsanların bu paralara güveni devam ettiği sürece kripto paraların varlığını koruyacağı, değerinde artış ve azalışlar olacağı gözlemlenmiş, güvenin yok olması durumunda ise etkinliklerini devam ettiremeyeceği tespit edilmiştir.
Summary Proof of stake (PoS) protocols rely on voting mechanisms to reach consensus on the current state. If an enhanced majority of staking nodes, also called validators , agree on a proposed block, then this block is appended to the blockchain. Yet these protocols remain vulnerable to faults caused by validators who abstain either accidentally or maliciously. To protect against such faults while retaining the PoS selection and reward allocation schemes, we study weighted voting in validator committees. We formalize the block creation process and introduce validators' voting profiles which we update by a multiplicative weights algorithm relative to validators' voting behavior and aggregate blockchain rewards. Using this framework, we leverage weighted majority voting rules that optimize collective decision making to show, both numerically and analytically, that the consensus mechanism is more robust if validators' votes are appropriately scaled. We raise potential issues and limitations of weighted voting in trustless, decentralized networks and relate our results to the design of current PoS protocols.
In this paper we address the issue of identity and access control within\nshared permissioned blockchains. We propose the ChainAchor system that provides\nanonymous but verifiable identities for entities on the blockchain. ChainAchor\nalso provides access control to entities seeking to submit transactions to the\nblockchain to read/verify transactions on the the permissioned blockchain.\nConsensus nodes enforce access control to the shared permissioned blockchain by\na simple look-up to a (read-only) list of anonymous members' public-keys.\nChainAnchor also provides unlinkability of transactions belonging to an entity\non the blockchain. This allows for an entity to optionally disclose their\nidentity when a transaction is called into question (e.g. regulatory or\ncompliance requirements), but without affecting the anonymity and unlinkability\nof their remaining transactions.\n
Software Defined Networking (SDN) is being extensively adopted by researchers and enterprise networks due to its feature of decoupling data and control planes from network device which enables them to implement new networking ideas. Communication between data and control planes faces various security issues where many users in data plane approach controller device in control plane to gain networking policies. In this paper, we proposed an efficient Zero-knowledge proof based identification scheme for securing SDN controller during data and control plane communication. This scheme ensures that only users who prove their knowledge about secrecy without revealing actual secret or any other information about it can communicate with controller. The computation cost was calculated to validate efficiency of the proposed work and compared with scheme that works in the basis of Kerberos authentication protocol.
We describe the design and implementation of GNU Taler, an electronic payment system based on an extension of Chaumian online e-cash with efficient change. In addition to anonymity for customers, it provides the novel notion of income transparency, which guarantees that merchants can reliably receive a payment from an untrusted payer only when their income from the payment is visible to tax authorities. Income transparency is achieved by the introduction of a refresh protocol, which gives anonymous change for a partially spent coin without introducing a tax evasion loophole. In addition to income transparency, the refresh protocol can be used to implement Camenisch-style atomic swaps, and to preserve anonymity in the presence of protocol aborts and crash faults with data loss by participants. Furthermore, we show the provable security of our income-transparent anonymous e-cash, which, in addition to the usual anonymity and unforgeability proper- ties of e-cash, also formally models conservation of funds and income transparency. Our implementation of GNU Taler is usable by non-expert users and integrates with the modern Web architecture. Our payment platform addresses a range of practical issues, such as tipping customers, providing refunds, integrating with banks and know-your-customer (KYC) checks, as well as Web platform security and reliability requirements. On a single machine, we achieve transaction rates that rival those of global, commercial credit card processors. We increase the robustness of the exchange—the component that keeps bank money in escrow in exchange for e-cash—by adding an auditor component, which verifies the correct operation of the system and allows to detect a compromise or misbehavior of the exchange early. Just like bank accounts have reason to exist besides bank notes, e-cash only serves as part of a whole payment system stack. Distributed ledgers have recently gained immense popularity as potential replacement for parts of the traditional financial industry. While cryptocurrencies based on proof-of-work such as Bitcoin have yet to scale to be useful as a replacement for established payment systems, other more efficient systems based on Blockchains with more classical consensus algorithms might still have promising applications in the financial industry. We design, implement and analyze the performance of Byzantine Set Union Consensus (BSC), a Byzantine consensus protocol that agrees on a (super-)set of elements at once, instead of sequentially agreeing on the individual elements of a set. While BSC is interesting in itself, it can also be used as a building block for permissioned Blockchains, where—just like in Nakamoto-style consensus—whole blocks of transactions are agreed upon at once, increasing the transaction rate.
The Internet of Things (IoT) is experiencing explosive growth and has gained extensive attention from academia and industry in recent years. Most of the existing IoT infrastructures are centralized, in which the presence of a cloud server is mandatory. However, centralized frameworks suffer from the issues of unscalability and single-point-of-failure. Consequently, decentralized IoT has been proposed by taking advantage of the emerging technology of Blockchain. Voting systems are widely adopted in IoT, such as a leader election in wireless sensor networks. Self-tallying voting systems are alternatives to traditional centralized voting systems in decentralized IoT since the traditional ones are not suitable for such scenarios. Unfortunately, self-tallying voting systems inherently suffer from fairness issues, such as adaptive and abortive issues caused by malicious voters. In this paper, we introduce a framework of self-tallying systems in decentralized IoT based on Blockchain. We propose a concrete construction and prove the proposed system satisfies all the security requirements including fairness, dispute-freeness and maximal ballot secrecy. The implementations on mobile phones demonstrate the practicability of our system.
Muhammad Saad, Victor Cook, Lan N. Nguyen, My T. Thai · 5 authors
In this paper, we explore the partitioning attacks on the Bitcoin network, which is shown to exhibit spatial bias, and temporal and logical diversity. Through data-driven study we highlight: 1) the centralization of Bitcoin nodes across autonomous systems, indicating the possibility of BGP attacks, 2)the non-uniform consensus among nodes, that can be exploited to partition the network, and 3)the diversity in the Bitcoin software usage that can lead to privacy attacks. Atop the prior work, which focused on spatial partitioning, our work extends the analysis of the Bitcoin network to understand the temporal and logical effects on the robustness of the Bitcoin network.
The Ethereum block chain as a decentralized platform is so successful that many applications deployed on it. However, for the inherent transparency properties and the lack of privacy, deploying a financial application on top of it is always a challenge. In this paper, we tackle this challenge and propose an anonymous sealed-bid auction protocol based on time-released encryption atop Consortium Block chain. We adopt a strict digital certificate-based identity mechanism of the consortium block chain to permit legitimate participants, and utilize the blind signature based on elliptic curve technology to allowing anonymous participation. Moreover, a timed release public key encryption algorithm is adopted to encrypt bids and prevent auctioneer from colluding with bidders. This is completely different from the method (zero-knowledge proof) used in other papers to prevent collusion between auctioneer and bidder. We provide a specific analysis of our protocol, which shows that our protocol meets anonymity and applicability.
Public key infrastructures (PKIs) are one of the main building blocks for securing communications over the Internet. Currently, PKIs are under the control of centralized authorities, which is problematic as evidenced by numerous incidents where they have been compromised. The distributed, fault tolerant log of transactions provided by blockchains and more recently, smart contract platforms, constitutes a powerful tool for the decentralization of PKIs. To verify the validity of identity records, blockchain-based identity systems store on chain either all identity records, or, a small (or even constant) sized amount of data for verifying identity records stored off chain. However, as most of these systems have never been implemented, there is little information regarding the practical implications of each design's tradeoffs. In this work, we first implement and evaluate the only provably secure, smart contract based PKI of Patsonakis et al. on top of Ethereum. This construction incurs constant-sized storage at the expense of computational complexity. To explore this tradeoff, we propose and implement a second construction which, eliminates the need for trusted setup, preserves the security properties of Patsonakis et al. and, as illustrated through our evaluation, is the only version with constant-sized state that can be deployed on the live chain of Ethereum. Furthermore, we compare these two systems with the simple approach of most prior works, e.g., the Ethereum Name Service, where all identity records are stored on the smart contract's state, to illustrate several shortcomings of Ethereum and its cost model. We propose several modifications for fine tuning the model, which would be useful to be considered for any smart contract platform like Ethereum so that it reaches its full potential to support arbitrary distributed applications.
Vincent Messié, Gaël Fromentoux, Xavier Marjou, Nathalie Labidurie Omnes
In this article, we highlight a novel solution for densifying 5G access networks. Taking benefits from local actors and prosumers, our proposal allows offering a better connectivity to end-users in a model involving network operators and a crowd of local actors. We show that building a multi-actors and densified access network infrastructure has become possible in a distributed way. Incumbent actors with a large footprint act as trusted partners securing the infrastructure and providing guarantees, while the crowd of local actors deploys multiple access points and are rewarded for their contribution. Rewarding is possible thanks to a distributed Bandwidth & Identity ledger along with a Proof of Bandwidth (PoB) mechanism. This article presents the main principles of this new connectivity platform, BALAdIN (Bandwidth Ledger AccountIng Networks), which relies on a consortium blockchain with access control mechanisms removing communitarian Wifi and ad hoc networks drawbacks. Indeed, combining distributed ledgers and edge networks allows local actors to cooperate with trusted parties, which leverages the full potential of multi-actors access networks.