Understanding (Mis)Behavior on the EOSIO Blockchain

© 2020 Copyright is held by the owner/author(s). 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

Digital asset management via distributed ledgers

Distributed ledgers rose to prominence with the advent of Bitcoin, the first provably secure protocol to solve consensus in an open-participation setting. Following, active research and engineering efforts have proposed a multitude of applications and alternative designs, the most prominent being Proof-of-Stake (PoS). This thesis expands the scope of secure and efficient asset management over a distributed ledger around three axes: i) cryptography; ii) distributed systems; iii) game theory and economics. First, we analyze the security of various wallets. We start with a formal model of hardware wallets, followed by an analytical framework of PoS wallets, each outlining the unique properties of Proof-of-Work (PoW) and PoS respectively. The latter also provides a rigorous design to form collaborative participating entities, called stake pools. We then propose Conclave, a stake pool design which enables a group of parties to participate in a PoS system in a collaborative manner, without a central operator. Second, we focus on efficiency. Decentralized systems are aimed at thousands of users across the globe, so a rigorous design for minimizing memory and storage consumption is a prerequisite for scalability. To that end, we frame ledger maintenance as an optimization problem and design a multi-tier framework for designing wallets which ensure that updates increase the ledger’s global state only to a minimal extent, while preserving the security guarantees outlined in the security analysis. Third, we explore incentive-compatibility and analyze blockchain systems from a micro and a macroeconomic perspective. We enrich our cryptographic and systems' results by analyzing the incentives of collective pools and designing a state efficient Bitcoin fee function. We then analyze the Nash dynamics of distributed ledgers, introducing a formal model that evaluates whether rational, utility-maximizing participants are disincentivized from exhibiting undesirable infractions, and highlighting the differences between PoW and PoS-based ledgers, both in a standalone setting and under external parameters, like market price fluctuations. We conclude by introducing a macroeconomic principle, cryptocurrency egalitarianism, and then describing two mechanisms for enabling taxation in blockchain-based currency systems

On the Behavioural Profiling of Gamblers using Cryptocurrency Transaction Data

Blockchain technologies enable a number of new ways to gamble online. Very little is known about engagement with one such new way of gambling: decentralised gambling applications, which provide simple casino games like dice rolls and coin flips. This is important as understanding engagement with any type of gambling is a crucial first step to assessing the risk of experiencing gambling related harm within the population. This thesis first surveys existing literature for methods of describing engagement in gambling, and then applies these methods to actual transaction data gathered from several decentralised gambling applications. This replication-oriented approach means results can be grounded against existing findings, and the descriptions of player engagement in this new domain have some context for comparison. It also means that descriptions can be tentatively mapped to similar scenarios, such as risk of experiencing gambling related harm in other studies. The results of several replication oriented studies presented herein find that engagement in the decentralised gambling domain is typically less than in comparable online casino games, but that a heavily involved subgroup is more involved. It also finds that engagement with gambling- like mechanisms in blockchain games is much less than in decentralised gambling applications, guiding future studies in gambling research away from blockchain games despite their mechanical similarities. Finally, behavioural groups in the decentralised gambling domain do not appear to be comparable with existing research in the centralised online casino game domain. The results of these studies provide a first look at engagement in this emerging domain, a comparative description with similar forms of gambling, and a description of behavioural groups, which provides essential context for further research to asses the scale of the risk of experiencing gambling related harm