238 citations · 469 across the 34 of their papers we have counts for
35 papers
Selfish Mining in Multi-Attacker Scenarios: An Empirical Evaluation of Nakamoto, Fruitchain, and Strongchain
Martin Perešíni, Tomáš Hladký, Jakub Kubík +1
The aim of this work is to enhance blockchain security by deepening the understanding of selfish mining attacks in various consensus protocols, especially the ones that have the po…
Analysing Multidisciplinary Approaches to Fight Large-Scale Digital Influence Operations
David Arroyo, Rafael Mata Milla, Marc Almeida Ros +4
Crime as a Service (CaaS) has evolved from isolated criminal incidents to a broad spectrum of illicit activities, including social media manipulation, foreign information manipulat…
Towards Secure Decentralized Applications and Consensus Protocols in Blockchains (on Selfish Mining, Undercutting Attacks, DAG-Based Blockchains, E-Voting, Cryptocurrency Wallets, Secure-Logging, and CBDC)
Ivan Homoliak
With the rise of cryptocurrencies, many new applications built on decentralized blockchains have emerged. Blockchains are full-stack distributed systems where multiple sub-systems…
PoS-CoPOR: Proof-of-Stake Consensus Protocol with Native Onion Routing Providing Scalability and DoS-Resistance
Ivan Homoliak, Martin Perešíni, Marek Tamaškovič +3
Proof-of-Stake (PoS) consensus protocols often face a trade-off between performance and security. Protocols that pre-elect leaders for subsequent rounds are vulnerable to Denial-of…
SNARKChain: Proof-of-Useful-Work Blockchain Consensus with General-Purpose SNARK Marketplace
Samuel Oleksak, Richard Gazdik, Martin Peresini +1
Proof of Work (PoW) is widely regarded as the most secure permissionless blockchain consensus protocol. However, its reliance on computationally intensive yet externally useless pu…
Secret Leader Election in Ethereum PoS: An Empirical Security Analysis of Whisk and Homomorphic Sortition under DoS on the Leader and Censorship Attacks
Tereza Burianová, Martin Perešíni, Ivan Homoliak
Proposer anonymity in Proof-of-Stake (PoS) blockchains is a critical concern due to the risk of targeted attacks such as malicious denial-of-service (DoS) and censorship attacks. W…
Generative Adversarial Networks Applied for Privacy Preservation in Biometric-Based Authentication and Identification
Lubos Mjachky, Ivan Homoliak
Biometric-based authentication systems are getting broadly adopted in many areas. However, these systems do not allow participating users to influence the way their data is used. F…
VoteMate: A Decentralized Application for Scalable Electronic Voting on EVM-Based Blockchain
Ivan Homoliak, Tomáš Švondr
Voting is a cornerstone of democracy, allowing citizens to express their will and make collective decisions. With advancing technology, online voting is gaining popularity as it en…
Proof-of-Social-Capital: A Consensus Protocol Replacing Stake for Social Capital
Juraj Mariani, Ivan Homoliak
Consensus protocols used today in blockchains often rely on computational power or financial stakes - scarce resources. We propose a novel protocol using social capital - trust and…
SoK: Cryptocurrency Mixing and Anonymity - Architectures, Threat Models, Operational Aspects and Security
Juraj Mariani, Ivan Homoliak, Martin Perešíni
Public blockchains record transaction histories that enable address clustering, taint analysis, and cross-service attribution, thereby motivating the development of mixers and priv…
FeatherWallet: A Lightweight Mobile Cryptocurrency Wallet Using zk-SNARKs
Martin Perešíni, Ivan Homoliak, Samuel Olekšák +1
Traditionally, mobile wallets rely on a trusted server that provides them with a current view of the blockchain, and thus, these wallets do not need to validate the header chain or…
Enhancing Security of AI-Based Code Synthesis with GitHub Copilot via Cheap and Efficient Prompt-Engineering
Jakub Res, Ivan Homoliak, Martin Perešíni +3
AI assistants for coding are on the rise. However one of the reasons developers and companies avoid harnessing their full potential is the questionable security of the generated co…
SoK: Cryptocurrency Wallets -- A Security Review and Classification based on Authentication Factors
Ivan Homoliak, Martin Perešíni
In this work, we review existing cryptocurrency wallet solutions with regard to authentication methods and factors from the user's point of view. In particular, we distinguish betw…
DAG-Sword: A Simulator of Large-Scale Network Topologies for DAG-Oriented Proof-of-Work Blockchains
Martin Perešíni, Tomáš Hladký, Kamil Malinka +1
The blockchain brought interesting properties for many practical applications. However, some properties, such as the transaction processing throughput remained limited, especially…
CBDC-AquaSphere: Interoperable Central Bank Digital Currency Built on Trusted Computing and Blockchain
Ivan Homoliak, Martin Perešíni, Patrik Holop +2
The adoption of decentralized, tamper-proof ledger systems is paving the way for new applications and opportunities in different contexts. While most research aims to improve their…
Incentive Attacks on DAG-Based Blockchains with Random Transaction Selection
Martin Perešíni, Ivan Homoliak, Federico Matteo Benčić +2
Several blockchain consensus protocols proposed to use of Directed Acyclic Graphs (DAGs) to solve the limited processing throughput of traditional single-chain Proof-of-Work (PoW)…
Fee-Redistribution Smart Contracts for Transaction-Fee-Based Regime of Blockchains with the Longest Chain Rule
Rastislav Budinský, Ivan Homoliak, Ivana Stančíková
In this paper, we review the undercutting attacks in the transaction-fee-based regime of proof-of-work (PoW) blockchains with the longest chain fork-choice rule. Next, we focus on…
Detecting and Preventing Credential Misuse in OTP-Based Two and Half Factor Authentication Toward Centralized Services Utilizing Blockchain-Based Identity Management
Jozef Drga, Ivan Homoliak, Juraj Vančo +2
This work focuses on the problem of detection and prevention of stolen and misused secrets (such as private keys) for authentication toward centralized services. We propose a solut…
SBvote: Scalable Self-Tallying Blockchain-Based Voting
Ivana Stančíková, Ivan Homoliak
Decentralized electronic voting solutions represent a promising advancement in electronic voting. One of the e-voting paradigms, the self-tallying scheme, offers strong protection…
DAG-Oriented Protocols PHANTOM and GHOSTDAG under Incentive Attack via Transaction Selection Strategy
Martin Perešíni, Federico Matteo Benčić, Kamil Malinka +1
In response to the bottleneck of processing throughput inherent to single chain PoW blockchains, several proposals have substituted a single chain for Directed Acyclic Graphs (DAGs…
Always on Voting: A Framework for Repetitive Voting on the Blockchain
Sarad Venugopalan, Ivana Stančíková, Ivan Homoliak
Elections repeat commonly after a fixed time interval, ranging from months to years. This results in limitations on governance since elected candidates or policies are difficult to…
BBB-Voting: 1-out-of-k Blockchain-Based Boardroom Voting
Sarad Venugopalan, Ivan Homoliak, Zengpeng Li +1
Voting is a means to agree on a collective decision based on available choices (e.g., candidates), where participants agree to abide by their outcome. To improve some features of e…
Intercepting Hail Hydra: Real-Time Detection of Algorithmically Generated Domains
Fran Casino, Nikolaos Lykousas, Ivan Homoliak +2
A crucial technical challenge for cybercriminals is to keep control over the potentially millions of infected devices that build up their botnets, without compromising the robustne…
CoinWatch: A Clone-Based Approach For Detecting Vulnerabilities in Cryptocurrencies
Qingze Hum, Wei Jin Tan, Shi Ying Tey +4
Cryptocurrencies have become very popular in recent years. Thousands of new cryptocurrencies have emerged, proposing new and novel techniques that improve on Bitcoin's core innovat…