Perhaps the most advanced application of the distributed ledger technology (DLT), the Blockchain is a decentralized system that is known to store immutable metadata with the use of robust cryptographic hashes and consensus mechanisms. The very foundation of the Blockchain is the establishment of trust-less transactions in peer-to-peer networks. Having been deemed to set off a whirlwind in Industry 4.0 as we know it and starting out with the groundbreaking Bitcoin, this relatively new technology is on the way to prove that it can find applications in almost every imaginable sector. While most people focus only on cryptocurrencies; this disruptive technology, in fact, offers utilities to many administrative operations, fintech procedures, and everyday services which could earlier only be done offline and/or in person, that can now be safely moved to the Internet as Software as a Service (SaaS) models. What makes Blockchain a powerful tool for digitalizing everyday facilities is the introduction of smart contracts, as brought forward foremost by the Ethereum platform. Considering today"s technology, Blockchain may create one of the most prominent alternatives to traditional voting in terms of security, consistency and speed. The Blockchain technology, fortified by Smart Contracts, enables enhanced data verifiability and lowered costs while maintaining the openness and transparency of the voting process. The anonymity of voters, the security of ballot transmission and the veracity of votes during the billing phase are the most fundamental requirements for voting. In this paper, a potential use case of Blockchain, an E-Voting protocol, is proposed, that utilizes the Blockchain as a transparent ballot box to cast votes.
E-Voting using Blockchain Technology - written by Abhishek Subhash Yadav , Yash Vandesh Urade , Ashish Uttamrao Thombare published on 2020/07/14 download full article with reference data and citations
Open access
Blockchain Technology Applications and Security
Internet Traffic Analysis and Secure E-voting
Advanced Steganography and Watermarking Techniques
We present a work in progress strategy for implementing privacy in Nano at the consensus level, that can be of independent interest. Nano is a cryptocurrency that uses an Open Representative Voting (ORV) as a consensus mechanism, a variant of Delegated Proof of Stake. Each transaction on the network is voted on by representatives and each vote has a weight equal to the percentage of their total delegated balance. Every account can delegate their stake to any other account (including itself) and change it anytime it wants. The fundamental goal of this paper is to construct a tool for the consensus algorithm to function without knowing the individual balances of each account. The tool is composed of three different schemes. The first is a weighted threshold secret sharing scheme based on Shamir's secret sharing scheme, used to generate a secret amongst a set of distributed parties, which will be a private key of an additive homomorphic ElGamal cryptosystem over elliptic curves. The second is a polynomials commitment scheme used to make the previous scheme verifiable, i.e., without the need for a trusted dealer. Finally, the third scheme is used to decrypt an ElGamal ciphertext without reconstructing the private key, which, because of this, can be used multiple times.
This project aims to create a blockchain-based model that addresses key challenges in digital voting. The goal is to develop a secure and transparent system that eliminates common issues such as delays in result announcements, voter identity verification concerns, and security risks [1]. Voting is the backbone of any democracy, and ensuring its integrity is crucial. Traditional digital voting systems often face problems like fraud, manipulation, and lack of transparency. Blockchain technology, with its decentralized and tamper-proof nature, offers a promising solution. It functions as a distributed ledger that records transactions securely in a peer-to-peer network, making it nearly impossible to alter past data [2]. This technology brings several benefits to voting, including decentralization, security, transparency, immutability, and voter anonymity [3]. A major highlight of this project is the integration of blockchain with smart contracts, which adds an extra layer of security and automation to the voting process [4]. The system is designed to work on the Ethereum blockchain, using smart contracts written in Solidity and accessed through blockchain wallets [5]. By eliminating the need for a central authority to oversee elections, this approach ensures a fair and transparent voting process where every vote is securely recorded and cannot be tampered with [6]. In essence, this project reimagines digital voting by leveraging blockchain’s strengths, making elections more secure, efficient, and trustworthy.
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Blockchain Technology Applications and Security
Internet Traffic Analysis and Secure E-voting
Advanced Steganography and Watermarking Techniques
Bithin Alangot, Daniël Reijsbergen, Sarad Venugopalan, Paweł Szałachowski
Clients of permissionless blockchain systems, like Bitcoin, rely on an\nunderlying peer-to-peer network to send and receive transactions. It is\ncritical that a client is connected to at least one honest peer, as otherwise\nthe client can be convinced to accept a maliciously forked view of the\nblockchain. In such an eclipse attack, the client is unable to reliably\ndistinguish the canonical view of the blockchain from the view provided by the\nattacker. The consequences of this can be catastrophic if the client makes\nbusiness decisions based on a distorted view of the blockchain transactions. In\nthis paper, we investigate the design space and propose two approaches for\nBitcoin clients to detect whether an eclipse attack against them is ongoing.\nEach approach chooses a different trade-off between average attack detection\ntime and network load. The first scheme is based on the detection of suspicious\nblock timestamps. The second scheme allows blockchain clients to utilize their\nnatural connections to the Internet (i.e., standard web activity) to gossip\nabout their blockchain views with contacted servers and their other clients.\nOur proposals improve upon previously proposed eclipse attack countermeasures\nwithout introducing any dedicated infrastructure or changes to the Bitcoin\nprotocol and network, and we discuss an implementation. We demonstrate the\neffectiveness of the gossip-based schemes through rigorous analysis using\noriginal Internet traffic traces and real-world deployment. The results\nindicate that our protocol incurs a negligible overhead and detects eclipse\nattacks rapidly with high probability, and is well-suited for practical\ndeployment.\n
Abstract Cryptocurrencies play a major role in the global financial ecosystem. Their presence across different geopolitical corridors, including in repressive regimes, has been one of their striking features. In this work, we leverage this feature for bootstrapping Censorship Resistant communication. We conceptualize the notion of stego-bootstrapping scheme and its security in terms of rareness and security against chosencovertext attacks. We present MoneyMorph , a provably secure stego-bootstrapping scheme using cryptocurrencies. MoneyMorph allows a censored user to interact with a decoder entity outside the censored region, through blockchain transactions as rendezvous, to obtain bootstrapping information such as a censorshipresistant proxy and its public key. Unlike the usual bootstrapping approaches (e.g., emailing) with heuristic security, if any, MoneyMorph employs public-key steganography over blockchain transactions to ensure provable cryptographic security. We design rendezvous over Bitcoin, Zcash, Monero, and Ethereum, and analyze their effectiveness in terms of available bandwidth and transaction cost. With its highly cryptographic structure, we show that Zcash provides 1148 byte bandwidth per transaction costing less than 0.01 USD as fee.
Learning from data owned by several parties, as in federated learning, raises challenges regarding the privacy guarantees provided to participants and the correctness of the computation in the presence of malicious parties. We tackle these challenges in the context of distributed averaging, an essential building block of federated learning algorithms. Our first contribution is a scalable protocol in which participants exchange correlated Gaussian noise along the edges of a network graph, complemented by independent noise added by each party. We analyze the differential privacy guarantees of our protocol and the impact of the graph topology under colluding malicious parties, showing that we can nearly match the utility of the trusted curator model even when each honest party communicates with only a logarithmic number of other parties chosen at random. This is in contrast with protocols in the local model of privacy (with lower utility) or based on secure aggregation (where all pairs of users need to exchange messages). Our second contribution enables users to prove the correctness of their computations without compromising the efficiency and privacy guarantees of the protocol. Our verification protocol relies on standard cryptographic primitives like commitment schemes and zero knowledge proofs.
In this note, we remark that the aggregation property of the BLS signature scheme yields an efficient Content Extraction Signature (CES). This construction can be used to build digital credentials that support selective disclosure in various settings. Interestingly, this construction is efficient and well suited to build credential issuance schemes with various applications in the client-server or in the distributed ledger models. Finally, we sketch a protocol that combines the CES with the use of a NIZK which allows to prove predicate satisfaction on claims extracted from a credential, while keeping the data secret.
Çalışmanın amacı, günümüz dijital çağında geleneksel muhasebe süreçlerinden teknolojik süreçlere geçişte blockchain (blok zinciri) teknolojisini muhasebe ve mali kontroller açısından incelemektir. Bu bağlamda çalışma, blok zinciri uygulamalarına, yol haritasına, kurumsal uygulamalarda blok zinciri etkinliğine ve blok zinciri temelli muhasebe sistemine odaklanmaktadır. Blok zinciri temelli üç taraflı muhasebe sistemi ile birlikte, Kurumsal Kaynak Planlama (ERP) sistemlerinin blok zinciri ile entegrasyonu ve teknolojinin bir diğer yönü olan kod ile yazılmış, belirli bir blok zinciri katmanına gömülü akıllı sözleşmeler detaylı olarak ele alınmıştır. Blok zinciri temelli üç taraflı muhasebe sistemi; çift girişli sistemin üzerine kurulacak, içine gömülü üçüncü bir blok zinciri katmanı olacak hem kurum içinde hem de dış taraflarla yapılan işlemleri kaydedecek bir sistem önermektedir.
Voting is a formal expression of one's choice.Though the process is simple, it has far-reaching and deep-lying impacts.Through a vote, people get a channel to voice their opinion anonymously.There are issues with the orthodox traditional voting system, which is used across the world today.Studies, presented throughout the paper, would highlight how millions of people have missed out on voicing their opinion, or get proper representation, due to the many short-comings of the dated traditional voting systems.Blockchain is a comparatively new technology.There have been advances and research made to make use of blockchains in the world of finance and ledger management.But precious little has been done to tackle simpler but widerreaching problems of voting.The novel approach suggested here would give the voters a chance to vote from the comfort of their homes, or, without adjusting their busy everyday schedules, and make sure everyone gets a proper representation as well.A combination of blockchain technology and fuzzy logic has been used here, to achieve a solution, that we think would help modernize the voting system and ensure greater satisfaction among the voters that their views have been represented in one way or the other.Using this novel approach, we believe that more people would be encouraged to vote and a greater number of voices would get proper representation.
EOSIO has become one of the most popular blockchain platforms since its mainnet launch in June 2018. In contrast to the traditional PoW-based systems (e.g., Bitcoin and Ethereum), which are limited by low throughput, EOSIO is the first high throughput Delegated Proof of Stake system that has been widely adopted by many decentralized applications. Although EOSIO has millions of accounts and billions of transactions, little is known about its ecosystem, especially related to security and fraud. In this paper, we perform a large-scale measurement study of the EOSIO blockchain and its associated DApps. We gather a large-scale dataset of EOSIO and characterize activities including money transfers, account creation and contract invocation. Using our insights, we then develop techniques to automatically detect bots and fraudulent activity. We discover thousands of bot accounts (over 30% of the accounts in the platform) and a number of real-world attacks (301 attack accounts). By the time of our study, 80 attack accounts we identified have been confirmed by DApp teams, causing 828,824 EOS tokens losses (roughly \$2.6 million) in total.
E-voting reduced the cost of election and provided convenience to some extent as compared to the traditional approach of pen and paper but it was considered to be unreliable as anyone having access to the machine physically can obstruct the machine and alter the votes. Also in order to control the e
Open access
Internet Traffic Analysis and Secure E-voting
Privacy, Security, and Data Protection
Advanced Steganography and Watermarking Techniques
Blok zincir (Blockchain) teknolojisinin bir ürünü olarak ortaya çıkan Bitcoin ve türevi kripto paralar son on yılın en önemli ekonomik yeniliğidir. Bitcoin, eşler arası veri paylaşım ağını (Peer-to-Peer) temel alan, merkezi bir otorite tarafından kontrol edilmeyen (decentralized), kamuya açık hesap kaydı tutma özelliğine sahip (PublicLedger), temelde online ödeme yapmayı sağlayan sanal bir para birimidir. Bitcoin, kripto paraların ekonomik olarak tanınmasında temel teşkil etmiştir. Bununla birlikte günümüzde genel veya özel fonksiyonlu pek çok Bitcoin türevi (Altcoin) kripto para birimi geliştirilmiştir. Kripto paralar her geçen gün daha fazla sayıda ticari işlemde kullanılmaya başlanmıştır. Kripto paralarla yapılan işlemlerin nasıl muhasebeleştirileceğine ilişkin henüz belirgin bir düzenleme bulunmaması farklı yaklaşımları da beraberinde getirmektedir. Bu çalışmanın amacı, mevcut yaklaşımlar ışığında kripto paraların nasıl muhasebeleştirilebileceğini tartışmaktır.<br>
According to the Internet Organised Crime Threat Assessment (IOCTA) 2019 report, Bitcoin is still the currency of choice in criminal markets and as payment for cyber-related extortion attempts, such as from ransomware or a Distributed Denial-of-Service (DDoS) attack. Bitcoin is a peer-to-peer electronic cash system first proposed by Satoshi Nakamoto in 2008. By design, Bitcoin is a pseudonymous coin, meaning that users can transact with the currency without revealing their true identity. To tackle the challenge of Bitcoin-related crime, a range of deanonymization techniques have been proposed. In general, these solutions are limited by the time and resources required to predict likely transaction owners. In this paper, we propose the first software-defined network (SDN)-based Bitcoin transaction mapping solution. We analyse the Bitcoin transaction process in an SDN environment and demonstrate a deterministic approach to deanonymize users in Bitcoin's network.
Ferenc Béres, István András Seres, András A. Benczúr, Mikerah Quintyne-Collins
Ethereum is the largest public blockchain by usage. It applies an account-based model, which is inferior to Bitcoin's unspent transaction output model from a privacy perspective. Due to its privacy shortcomings, recently several privacy-enhancing overlays have been deployed on Ethereum, such as non-custodial, trustless coin mixers and confidential transactions. In our privacy analysis of Ethereum's account-based model, we describe several patterns that characterize only a limited set of users and successfully apply these quasi-identifiers in address deanonymization tasks. Using Ethereum Name Service identifiers as ground truth information, we quantitatively compare algorithms in recent branch of machine learning, the so-called graph representation learning, as well as time-of-day activity and transaction fee based user profiling techniques. As an application, we rigorously assess the privacy guarantees of the Tornado Cash coin mixer by discovering strong heuristics to link the mixing parties. To the best of our knowledge, we are the first to propose and implement Ethereum user profiling techniques based on quasi-identifiers. Finally, we describe a malicious value-fingerprinting attack, a variant of the Danaan-gift attack, applicable for the confidential transaction overlays on Ethereum. By incorporating user activity statistics from our data set, we estimate the success probability of such an attack.
Dimitris Geneiatakis, Yannis Soupionis, Gary Steri, Ioannis Kounelis · 6 authors
With the continuous development of distributed ledger and blockchain technologies, new use cases apart from cryptocurrencies have come into the spotlight. In this article, we evaluate whether an e-government service could be a suitable candidate for a blockchain transformation. We selected as a reference test system an existing cross-border e-government service that is used for supporting goods exchanges across the European Union. We show how such an indicative paradigm can be transformed into a blockchain system. In order to do so, we deployed it in an emulated architecture for evaluating its performance under various realistic conditions. Our results show that the deployed system is able to meet the requirements, both in terms of throughput and transaction speed. Moreover, it shows clear advantages in terms of usability and synchronization between all entities.
This paper describes techniques to help with COVID-19 automated contact tracing, and with the restoration efforts. We describe a decentralized protocol for ``proof-of-contact'' in zero knowledge where a person can publish a short cryptographic proof attesting to the fact that they have been infected and that they have come in contact with a set of people without revealing any information about any of the people involved. More importantly, we describe how to compose these proofs to support broader functionality such as proofs of $n$th-order exposure which can further speed up automated contact tracing. The cryptographic proofs are publicly verifiable, and places the burden on the person proving contact and not on third parties or healthcare providers rendering the system more decentralized, and accordingly more scalable.
Jacob Swambo, Spencer Hommel, Bob McElrath, Bryan Bishop
A bitcoin \textit{covenant} is a mechanism to enforce conditions on future bitcoin transactions. A bitcoin \textit{vault} is a specific type of covenant transaction that enforces a time-lock on the transfer of control of funds to a hot wallet, but enables an immediate transfer of funds into a deep cold recovery wallet. This paper demonstrates how to integrate a bitcoin vault into a custody protocol and demonstrates the security properties of that protocol. The vault is implemented using pre-signed transactions with secure key deletion (as proposed in \cite{Swambo2020cov}). It is shown that vault-custody protocols enable the wallet owner to specify their desired balance for an inherent trade-off between the security of and accessibility of bitcoin holdings by adjusting the length of time-locks used. It is also demonstrated that wallet owners have increased control of risk-management by compartmentalizing funds across numerous vault transactions. While it isn't realistic to completely prevent theft, the most likely theft scenarios (compromising the hot wallet) have severely limited profitability for an attacker, deterring attempts at theft from the beginning. The proposed architecture was designed to offer defence-in-depth through redundancy and fault-tolerant functionality as well as countermeasures for class breaks through diversity across hardware and software layers. Finally, the architecture employs a detection (a watchtower) and response system that enables fail-safe recovery from attempted or partial thefts through a second type of covenant transaction, a push-to-recovery-wallet transaction.
E-voting is one of the valid use cases of blockchain technology with many blockchain e-voting systems already proposed. But efforts that focus on critical analysis of blockchain e-voting architectures for national elections from stakeholders’ perspectives are mostly lacking in the literature. Therefore, government decision-makers and election stakeholders do not yet have a sufficient basis to understand the potential risks, challenges, and prospects that are associated with blockchain e-voting. This paper demonstrates how the use of the Architecture Trade-off Analysis Method (ATAM) can enable stakeholders in national elections to understand the risks, prospects, and challenges that could be associated with a blockchain e-voting system for national elections. By using a study context of South Africa, a proposed blockchain e-voting architecture was used as a basis to aid election stakeholders to reason on the concept of blockchain e-voting to get them to understand the potential risks, security threats, critical requirements attributes, and weaknesses that could be associated with using blockchain e-voting for national elections. The study found that blockchain e-voting can prevent many security attacks, internal vote manipulation, and promote transparency. However, voter validation and the security of the blockchain architecture are potential weaknesses that will need significant attention.
Today, the entire world is facing incredible health and economic challenges due to the rapid spread of the life threatening novel Coronavirus Disease - 2019 (COVID-19). In the prevailing situation when a vaccine is many months away, the way forward seems to be a controlled exit from the lockdown - where, infected/exposed people are strictly quarantined and recovered/unexposed people are allowed to carry on with their day to day business activities. However, appropriate physical distancing norms will have to be strictly followed for such relaxations. Therefore, mechanisms are required that will assist people in following the social and physical distancing norms in public places. In this paper, we propose an anonymity preserving blockchain based framework that allows people, through use of their smart phones and other communication devices, to protect themselves from infections as they conduct their daily business activities.
Over the years, the flourish of crowd computing has enabled enterprises to accomplish computing tasks through crowdsourcing in a large-scale and high-quality manner, and therefore how to efficiently and securely implement crowd computing becomes a hotspot. Some recent work innovatively adopted a P2P (peer-to-peer) network as the communication environment of crowdsourcing. Based on its decentralized control, issues like single-point-of-failure or DDoS attack can be overcome to some extent, but the huge computing capacity and storage costs required by this scheme is always unbearable. Federated learning is a distributed machine learning that supports local storage of data, and clients implement training through interactive gradient values. In our work, we combine blockchain with federated learning and propose a crowdsourcing framework named CrowdSFL, that users can implement crowdsourcing with less overhead and higher security. In addition, to protect the privacy of participants, we design a new re-encryption algorithm based on Elgamal to ensure that interactive values and other information will not be exposed to other participants outside the workflow. Finally, we have proved through experiments that our framework is superior to some similar work in accuracy, efficiency, and overhead.