Kateryna Isirova, Анастасія Кіян, Mariia Rodinko, Alexandr Kuznetsov
Electronic trust services are becoming an integral part of the information space. With the reliable implementation of basic services as an electronic signature and electronic authentication, it is possible to build more complex systems that rely on them, particularly the electronic voting system. In the paper, the new concept for developing a decentralized electronic voting system using blockchain technology is proposed. The two-level architecture provides a secure voting process without redundancy of existing (not based on blockchain) systems. The presented blockchain-based voting protocol has six steps that ensure all requirements that are put forward to such types of protocols including voting transparency and anonymity.
A cryptocurrency is a decentralised digital currency that utilises blockchain technology to remove the role of a central authority. Monero is one of the cryptocurrencies that improves its anonymity by employing privacy-preserving cryptographic techniques, such as linkable ring signature. In this thesis, we explore three areas in Monero system that can cause anonymity problems. These areas are Monero transaction creation protocol, Monero protocol update, and Monero third-party services. We identify attack schemes to reduce honest users' transaction anonymity. We then investigate the impact of Monero protocol updates to transaction anonymity. Lastly, we study wallet service providers that can trace Monero transactions and mining pools that leak information.
Ordinos is a novel verifiable tally-hiding e-voting system. At its heart, a homomorphic encryption scheme and secure multi-party computation (MPC) are used to tally votes and securely determine the voting result, without necessarily revealing the full tally (e.g., the number of votes per candidate)The proof of concept implementation of Ordinos is based on a threshold variant of the Paillier encryption scheme and two MPC protocols for the comparison of encrypted numbers (greater-than and equality). Due to the threshold construction, the decryption key is shared among a set of trustees. The MPC protocols for comparison require precomputed encrypted randomness of certain shape. Formerly, a trusted party was employed to generate the key shares and randomness and distribute them to the trustees. In this thesis, the trusted party was replaced by MPC protocols that allow to generate the key shares and randomness among the trustees. The protocols provide security against malicious parties in the honest-majority setting. The key generation follows a proposal by Nishide and Sakurai (2010) that is based on verifiable secret sharings and zero-knowledge proofs for committed values. We introduce a few adaptations to reduce its runtime using mostly standard techniques. The generation of randomness is based on the Paillier encryption scheme as an arithmetic black box and standard zero-knowledge proofs for Paillier encrypted values. The protocols were implemented and their performance was evaluated in a local network. Most notablythe implemented key generation protocol for threshold Paillier showed an expected average runtime around 95 minutes for generating 2048-bit keys among 3 trustees with a threshold of 2. Since existing implementations provide security only in the semi-honest setting, this is the first time that an approach with security against malicious parties was implemented and evaluated. Overall, the distributed generation of both key shares and randomness takes considerably more time compared to the use of a trusted party, but avoids security risks and trust problems that occur with trusted parties.
Open access
Internet Traffic Analysis and Secure E-voting
Advanced Steganography and Watermarking Techniques
Although the launch of Internet Protocol version six (IPv6) addressed the issue of IPv4's address depletion, but also mandated the use of Internet Control Message Protocol version six (ICMPv6) messages in newly introduced features such as the Neighbor Discovery Protocol (NDP). This has exacerbated existing network attacks including ICMPv6-based Denial of Service (DoS) attacks and its variant form Distributed Denial of Service (DDoS) attack. Intrusion Detection Systems (IDS) aimed at tackling security issues raised by ICMPv6-based DoS and DDoS attacks have been reviewed by researchers and a general classification of existing IDSs was proposed as anomaly-based and signature-based. However, it is incredibly hard to see the overall picture of IDSs based on Machine Learning (ML) techniques with such a classification, as there is a lack of a more detailed view of the ML approach, classifiers, feature selection techniques, datasets, and different evaluation metrics. Nevertheless, recent developments in this relatively new field have not been covered such as ML-based IDSs using flow-based traffic representation. Therefore, this article specifically reviews and classifies IDSs based on ML techniques to detect ICMPv6-based DoS and DDoS attacks as single and hybrid classifiers. In addition, blockchain applicability in Collaborative IDS (CIDS) architecture based on the ensemble framework has been proposed as a solution to one of the open challenges for ICMPv6-based DoS and DDoS attacks detection problem. Moreover, this review also provides a classification of ICMPv6 vulnerabilities to DoS and DDoS attacks which would provide a reference resource for future researchers in this domain. To the best of the author's knowledge, this is the first review paper specifically focusing on IDSs based on ML techniques in this domain, as well as blockchain applicability as a possible research direction has been proposed to attract researcher's focus on building ensemble learning-based IDS models.
The Onion Router (Tor) is one of the major network systems that provide anonymous communication and censorship circumvention. Tor enables its users to surf the Internet, chat, and send messages anonymously; however, cyber attackers also exploit the system for circumventing criminal activity detection. Recently, various approaches that prevent or mitigate abuse of Tor have been proposed in the literature. This paper, which presents one of the approaches, addresses an IP traceback problem. In our model, onion routers that voluntarily participate in attacker tracing detect attack packets (packets carrying an attacker's code or data) recorded in the log files by sharing necessary information with an attacked server over an Ethereum blockchain network. The detection algorithm in this paper uses the statistics of packet travel and relay times and outputs attack-packet candidates. The proposed method attaches a reliability degree to each candidate, which is based on the upper bounds of its Type I and II error rates. A smart contract running on the blockchain network ranks the detection results from onion routers according to the reliability degrees.
The inseparable internet requirements and the endless stream of cyber-attacks have led to strong demand for trusted IP addresses. However, the existing collaborative DNS security schemes have the defects of low credibility and imperfect incentive mechanism. Enlightened by the Consortium blockchain technology, we propose a novel DNS Cache Resources Trusted Sharing Model, which can improve the credibility of DNS resolution results by establishing a complete chain of trust. Firstly, the consortium blockchain is introduced as the carrier of the peer-to-peer network to reduce the impact of illegal access and complicity tampering on the DNS cache credibility; Secondly, the evaluation index of the node credibility in the DNS cache sharing model is proposed, and the trust-based incentive mechanism is designed to reduce the impact of free-riding behavior and on the trusted performance of the system. The two indicators of node abnormal behavior similarity and roundtrip time between nodes are used to comprehensively evaluate the degree of recommendation of the node and serve as the basis for dynamic scheduling; Finally, we use the stochastic distributed decentralized storage mechanism to solve the problem of low efficiency in the consortium blockchain. The simulation results show that the model has certain advantages in ensuring the credibility of domain name resolution results, and maintains the ideal efficiency while ensuring trust.
Identity is a tool that identifies a person or group and ensures that they are recognized by others. Personalidentification cards issued by the states to people contain specific information about the person given.Identity systems used for centuries are now digitalized, ID cards with chips and passports with chipshave entered our lives. In the past, only information such as name, surname and place of birth wereincluded in ID cards with chips and passports. But today, in addition to our personal information, itincludes our biometric information such as fingerprints, iris, digital signatures. Blockchain technology,which has entered our lives with the financial sector, offers application areas in different sectors andsubjects. Some of these are IoT (internet of things), security and reliability systems, copyrights, publicand health sectors. In this study, it has been mentioned about the advantages and the features obtainedby using blockchain technology in identity management. The purpose of this study; It is to ensure thesafe use of identity information thanks to the features provided by the block chain such as distributeddatabase called DLT (distributed ledger technology), peer-to-peer transmission, transparency andirreversible records. Also in this study, a software that can simulate blockchain technology was createdand an Android application that reads data with NFC (Near Field Communication) technology wasdeveloped. Thus, the process of adding the data in the ID card or passport to the block chain by readingthe data from NFC with the Android application can be performed.
Mahmoud El-Gayyar, Hany F. ElYamany, Katarina Grolinger, Miriam A. M. Capretz · 5 authors
A federated identity is a single identity that enables users to access multiple services across a network of business parties. Such identities are subject to various threats and attacks and face diverse challenges including identity leaks, centralised management, auditing limitations, and long breach investigation processes. This paper proposes a framework aimed at automating and decentralising the generation and auditing of a robust and secured blockchain-based federated identity in a marketplace. Business parties participating in the marketplace form the nodes of a distributed blockchain network and participate in the creation of federated identities. Users of this network can access services provided by any one of the participating parties using a single federated identity. All transactions are fully audited in the blockchain, meaning that participating parties can monitor access to their service and users can trace the use of their identities. The proposed framework has been evaluated using two blockchain technologies (Ethereum and Hyperledger Fabric) to measure its performance in public and permissioned blockchain environments.
A blockchain-enabled online-voting system is being proposed in this following paper. Blockchain technologies deliver an endless variety of applications that benefit from distributed economies. The proposed model is an android application that has enhanced security features which includes both authentication and authorization. Authentication is incorporated by using a unique identification key and authorization is done by using fingerprint. Voters are also being verified by One-time password. The security in this project is implemented by using a 128 bit AES encryption algorithm and SHA-256 along with blockchain. The vote is casted in the form of transaction, where a blockchain is created, which keeps track of tallies of votes. Through this atomicity and integrity are maintained. [4] Index Terms—Voting System , Blockchain , SHA-256, Security, AES-128, Ballot
Open access
Internet Traffic Analysis and Secure E-voting
Blockchain Technology Applications and Security
Advanced Steganography and Watermarking Techniques
Over the past twenty years, the number of devices connected to the Internet grew exponentially. Botnets benefited from this rise to increase their size and the magnitude of their attacks. However, they still have a weak point in their Command & Control (C&C) system, which is often based on centralized services or require a complex infrastructure to keep operating without being taken down by authorities. The recent spread of blockchain technologies may give botnets a powerful tool to make them very hard to disrupt. Recent research showed how it is possible to embed C&C messages in Bitcoin transactions, making them nearly impossible to block. Nevertheless, transactions have a cost and allow very limited amounts of data to be transmitted. Because of that, only messages from the botmaster to the bots are sent via Bitcoin, while bots are assumed to communicate through external channels. Furthermore, for the same reason, Bitcoin-based messages are sent in clear. In this paper we show how, using Bitcoin Testnet, it is possible to overcome these limitations and implement a cost-free, bidirectional, and encrypted C&C channel between the botmaster and the bots. We propose a communication protocol and analyze its viability in real life. Our results show that this approach would enable a botmaster to build a robust and hard-to-disrupt C&C system at virtually no cost, thus representing a realistic threat for which countermeasures should be devised.
Utz Nisslmueller, Klaus-Tycho Foerster, Stefan Schmid, Christian Decker
Cryptocurrency off-chain networks such as Lightning (e.g., Bitcoin) or Raiden (e.g., Ethereum) aim to increase the scalability of traditional on-chain transactions. To support nodes in learning about possible paths to route their transactions, these networks need to provide gossip and probing mechanisms. This paper explores whether these mechanisms may be exploited to infer sensitive information about the flow of transactions, and eventually harm privacy. In particular, we identify two threats, related to an active and a passive adversary. The first is a probing attack: here the adversary aims to detect the maximum amount which is transferable in a given direction over a target channel by actively probing it and differentiating the response messages it receives. The second is a timing attack: the adversary discovers how close the destination of a routed payment actually is, by acting as a passive man-in-the middle and analyzing the time deltas between sent messages and their corresponding responses. We then analyze the limitations of these attacks and propose remediations for scenarios in which they are able to produce accurate results.
E-voting is the process of conducting the voting process through online. The voters can cast their votes from different locations and these votes are collected and recorded electronically. Therefore, there is a need for a system to provide control and security to the whole procedure. Blockchain, a distributed ledger technology can be integrated to provide a decentralized system. Blockchain uses distributed ledger technology (DLT) to avoid forged voting option & non-repudiation and one time login of the user is also ensured. By integrating the above techniques, a secure user authentication for e-voting supported blockchain in p2p network is projected. This system would increase the safety by avoiding the forgery of votes. Similarly, the blockchain are often integrated to a spread of voting situations and a few alternative applications.
Open access
2 source records
Blockchain Technology Applications and Security
Internet Traffic Analysis and Secure E-voting
Advanced Steganography and Watermarking Techniques
Zongyang Zhang, Weihan Li, Haitao Liu, Jianwei Liu
With the continuous development and popularity of blockchain technology, anonymity of cryptocurrency has attracted wide attention. Zcash is an altcoin of Bitcoin aiming to protect blockchain anonymity. Its anonymity is highly guaranteed by zero-knowledge proofs. However, it is still practicable to decrease Zcash's anonymity. In this paper, we provide a refined empirical analysis of Zcash anonymity. We improve current address clustering methods and increase the clustering rate by 9%. We also analyze the whole process of distributing mining reward and identify 87.5% addresses and 25.7% transactions. Besides, we simplify Zcash transaction network and then pick out nodes (edges) which play important roles in network connectivity. We show that these nodes are mostly mining pools. In particular, users participating in shieldedpool are mostly founders, miners and mining pools, although shieldedpool itself is designed for protecting anonymity of users with high privacy requirements. Our results, to an extent, are opposite to the original intention of Zcash.
Anita A. Lahane, Junaid Patel, Talif Pathan, Prathmesh Potdar
Election could be a important event during a trendy democracy however massive sections of society round the world don’t trust their election system that is major concern for the democracy. Even the world’s largest democracies like Republic of India, us, and Japan still suffer from a blemished legal system. Vote rigging, hacking of the EVM (Electronic vote machine), election manipulation, and booth capturing square measure the key problems within the current electoral system. during this system, we tend to square measure work the problems|the problems within the election vote systems and attempting to propose the E-voting model which might resolve these issues. The system can highlight a number of the popular blockchain frameworks that provide blockchain as a service and associated electronic E-voting system that is predicated on blockchain that addresses all limitations severally, it additionally preserve participant’s obscurity whereas still being hospitable public examination. Building Associate in Nursing electronic electoral system that satisfies the legal necessities of legislators has been a challenge for an extended time. Distributed ledger technologies is Associate in Nursing exciting technological advancement within the info technology world. Blockchain technologies supply Associate in Nursing infinite vary of applications cashing in on sharing economies. Blockchain could be a unquiet technology of current era and guarantees to enhance the resilience of e-voting systems. this technique presents a shot to leverage edges of blockchain like cryptological foundations and transparency to attain an efficient theme for e-voting. The projected theme conforms to the elemental necessities for e-voting schemes and achieves end-to-end verifiability. The system presents in-depth analysis of the theme that with success demonstrates its effectiveness to attain Associate in Nursing end-to-end verifiable e-voting theme.
Open access
Internet Traffic Analysis and Secure E-voting
Network Security and Intrusion Detection
Advanced Steganography and Watermarking Techniques
We present a modification to RingCT protocol with stealth addresses that makes it compatible with Delegated Proof of Stake based consensus mechanisms called Delegated RingCT.
Our scheme has two building blocks: a customised version of an Integrated Signature and Encryption scheme composed of a public key encryption scheme and two signature schemes (a digital signature and a linkable ring signature); and non-interactive zero knowledge proofs. We give a description of the scheme, security proofs and a prototype implementation whose benchmarking is discussed.
Although Delegated RingCT doesn't have the same degree of anonymity as other RingCT constructions, we argue that the benefits that the compatibility with DPoS consensus mechanisms brings constitutes a reasonable trade-off for being able to develop an anonymous decentralised cryptocurrency that is faster and more scalable than existing ones.
Privacy-focused crypto-currencies, such as Zcash or Monero, aim to provide strong cryptographic guarantees for transaction confidentiality and unlinkability.In this paper, we describe side-channel attacks that let remote adversaries bypass these protections.We present a general class of timing side-channel and traffic-analysis attacks on receiver privacy.These attacks enable an active remote adversary to identify the (secret) payee of any transaction in Zcash or Monero.The attacks violate the privacy goals of these crypto-currencies by exploiting side-channel information leaked by the implementation of different system components.Specifically, we show that a remote party can link all transactions that send funds to a user, by measuring the response time of that user's P2P node to certain requests.The timing differences are large enough that the attacks can be mounted remotely over a WAN.We responsibly disclosed the issues to the affected projects, and they have patched the vulnerabilities.We further study the impact of timing side-channels on the zero-knowledge proof systems used in these cryptocurrencies.We observe that in Zcash's implementation, the time to generate a zero-knowledge proof depends on secret transaction data, and in particular on the amount of transacted funds.Hence, an adversary capable of measuring proof generation time could break transaction confidentiality, despite the proof system's zero-knowledge property.Our attacks highlight the dangers of side-channel leakage in anonymous crypto-currencies, and the need to systematically protect them against such attacks.