Author
Vasileios Glykantzis
Bio: Vasileios Glykantzis is an academic researcher from ETH Zurich. The author has contributed to research in topics: Proof-of-work system & Cryptocurrency. The author has an hindex of 2, co-authored 2 publications receiving 936 citations.
Papers
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24 Oct 2016
TL;DR: This paper introduces a novel quantitative framework to analyse the security and performance implications of various consensus and network parameters of PoW blockchains and devise optimal adversarial strategies for double-spending and selfish mining while taking into account real world constraints.
Abstract: Proof of Work (PoW) powered blockchains currently account for more than 90% of the total market capitalization of existing digital cryptocurrencies. Although the security provisions of Bitcoin have been thoroughly analysed, the security guarantees of variant (forked) PoW blockchains (which were instantiated with different parameters) have not received much attention in the literature. This opens the question whether existing security analysis of Bitcoin's PoW applies to other implementations which have been instantiated with different consensus and/or network parameters. In this paper, we introduce a novel quantitative framework to analyse the security and performance implications of various consensus and network parameters of PoW blockchains. Based on our framework, we devise optimal adversarial strategies for double-spending and selfish mining while taking into account real world constraints such as network propagation, different block sizes, block generation intervals, information propagation mechanism, and the impact of eclipse attacks. Our framework therefore allows us to capture existing PoW-based deployments as well as PoW blockchain variants that are instantiated with different parameters, and to objectively compare the tradeoffs between their performance and security provisions.
1,258 citations
Posted Content•
TL;DR: In this article, the authors introduce a quantitative framework to analyze the security and performance implications of various consensus and network parameters of PoW blockchains, and devise optimal adversarial strategies for double-spending and selfish mining.
Abstract: Proof of Work (PoW) powered blockchains currently account for more than 90% of the total market capitalization of existing digital cryptocurrencies. Although the security provisions of Bitcoin have been thoroughly analysed, the security guarantees of variant (forked) PoW blockchains (which were instantiated with different parameters) have not received much attention in the literature. This opens the question whether existing security analysis of Bitcoin's PoW applies to other implementations which have been instantiated with different consensus and/or network parameters. In this paper, we introduce a novel quantitative framework to analyse the security and performance implications of various consensus and network parameters of PoW blockchains. Based on our framework, we devise optimal adversarial strategies for double-spending and selfish mining while taking into account real world constraints such as network propagation, different block sizes, block generation intervals, information propagation mechanism, and the impact of eclipse attacks. Our framework therefore allows us to capture existing PoW-based deployments as well as PoW blockchain variants that are instantiated with different parameters, and to objectively compare the tradeoffs between their performance and security provisions.
29 citations
Cited by
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TL;DR: Wang et al. as discussed by the authors conduct a systematic study on the security threats to blockchain and survey the corresponding real attacks by examining popular blockchain systems. And they also review the security enhancement solutions for blockchain, which could be used in the development of various blockchain systems, and suggest some future directions to stir research efforts into this area.
1,071 citations
22 Apr 2017
TL;DR: This work analyses the security vulnerabilities of Ethereum smart contracts, providing a taxonomy of common programming pitfalls which may lead to vulnerabilities, and shows a series of attacks which exploit these vulnerabilities, allowing an adversary to steal money or cause other damage.
Abstract: Smart contracts are computer programs that can be correctly executed by a network of mutually distrusting nodes, without the need of an external trusted authority. Since smart contracts handle and transfer assets of considerable value, besides their correct execution it is also crucial that their implementation is secure against attacks which aim at stealing or tampering the assets. We study this problem in Ethereum, the most well-known and used framework for smart contracts so far. We analyse the security vulnerabilities of Ethereum smart contracts, providing a taxonomy of common programming pitfalls which may lead to vulnerabilities. We show a series of attacks which exploit these vulnerabilities, allowing an adversary to steal money or cause other damage.
988 citations
TL;DR: This paper introduces blockchain technologies, including their benefits, pitfalls, and the latest applications, to the biomedical and health care domains and discusses the potential challenges and proposed solutions of adopting blockchain technologies in biomedical/health care domains.
798 citations
20 Jun 2018
TL;DR: This paper critically analyze whether a blockchain is indeed the appropriate technical solution for a particular application scenario, and distinguishes between permissionless and permissioned blockchains and contrast their properties to those of a centrally managed database.
Abstract: Blockchain is being praised as a technological innovation which allows to revolutionize how society trades and interacts This reputation is in particular attributable to its properties of allowing mutually mistrusting entities to exchange financial value and interact without relying on a trusted third party A blockchain moreover provides an integrity protected data storage and allows to provide process transparency In this paper we critically analyze whether a blockchain is indeed the appropriate technical solution for a particular application scenario We differentiate between permissionless (eg, Bitcoin/Ethereum) and permissioned (eg Hyperledger/Corda) blockchains and contrast their properties to those of a centrally managed database We provide a structured methodology to determine the appropriate technical solution to solve a particular application problem Given our methodology, we analyze in depth three use cases - Supply Chain Management, Interbank and International Payments, and Decentralized Autonomous Organizations and conclude the article with an outlook for further opportunities
794 citations
TL;DR: Although the feature of blockchain technologies may bring us more reliable and convenient services, the security issues and challenges behind this innovative technique is also an important topic that the authors need to concern.
Abstract: Blockchain technologies is one of the most popular issue in recent years, it has already changed people's lifestyle in some area due to its great influence on many business or industry, and what it can do will still continue cause impact in many places Although the feature of blockchain technologies may bring us more reliable and convenient services, the security issues and challenges behind this innovative technique is also an important topic that we need to concern
756 citations