{"title":"Push and Pull: Manipulating a Production Schedule and Maximizing Rewards on the EOSIO Blockchain","authors":"Dongsoo Lee, Dong Hoon Lee","doi":"10.1145/3327959.3329538","DOIUrl":"https://doi.org/10.1145/3327959.3329538","url":null,"abstract":"EOSIO is a blockchain platform utilizing a byzantine-fault-tolerance delegated-proof-of-stake (BFT-DPOS) consensus protocol to guarantee scalability. In EOSIO, a group of representatives called block producers (BPs) is elected by voting through a certain period, and is scheduled in an order to produce blocks. And new tokens are given to BPs every time they produce a block as a notion of reward. In this paper, we show that an attacker can disturb fairness of compensation policy by manipulating the production schedule of EOSIO. Such manipulation is possible through an attacker who has enough tokens to abuse the election process. In order to demonstrate the feasibility and the capability of our attack, we created a tool following EOSIO's voting and irreversible block generation procedure. Our simulation shows that an attacker can provide additional rewards or loss up to 3 BPs. Finally, we discuss the applicability of our attack against the real EOSIO mainnet, and at the same time, propose some countermeasures to prevent it.","PeriodicalId":302776,"journal":{"name":"Proceedings of the Third ACM Workshop on Blockchains, Cryptocurrencies and Contracts","volume":"40 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129930617","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Colosseum: A Scalable Permissioned Blockchain over Structured Network","authors":"H. Gupta, D. Janakiram","doi":"10.1145/3327959.3329539","DOIUrl":"https://doi.org/10.1145/3327959.3329539","url":null,"abstract":"Permissioned blockchain protocols generally use voting based algorithms to reach consensus. Scaling such protocols is hard because of their high message complexity and thus, have a limited number of applications. Use cases like banking and healthcare blockchain require a scalable distributed protocol to maintain the consistency of the ledger and ensure its safety. This paper presents Colosseum, a scalable consensus protocol designed for permissioned blockchain systems. It is a knockout tournament based protocol over a structured ring network to reach consensus on the next set of block proposers. Participants compete in the rounds of a novel two-player game in each tournament to become eligible to propose block. Colosseum introduces Proof-of-Win as the certificate for the result of matches to have an efficient and easy way to propose trusted blocks and verify them.","PeriodicalId":302776,"journal":{"name":"Proceedings of the Third ACM Workshop on Blockchains, Cryptocurrencies and Contracts","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130869838","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Mayflies, Breeders, and Busy Bees in Ethereum: Smart Contracts Over Time","authors":"Monika di Angelo, G. Salzer","doi":"10.1145/3327959.3329537","DOIUrl":"https://doi.org/10.1145/3327959.3329537","url":null,"abstract":"Smart contracts on a blockchain are programs running in a distributed, transparent, and trustless environment, being one of the major assets of this new technology. They give rise to innovative applications and business models, with their potential and lasting impact still open. In this situation, it is interesting to understand what smart contracts are actually doing. While public announcements, by their nature, make promises of what smart contracts might achieve, the openly available data of blockchains provides a more balanced view on what is actually going on. In this paper, we analyze the activities of smart contracts on the Ethereum blockchain, the most prominent platform for smart contracts with all blockchain data visible. However, contracts operate behind the scenes. Their activities are only accessible by looking beyond the mere blockchain data that records external transactions. We also use all internal messages caused by contracts interacting with other addresses. In particular, we investigate the activities of smart contracts in their quantitative and temporal aspects. Based on lifespan and activity patterns, we identify particular groups like mayflies, loners, breeders, busy bees, sleepers, self-destructed and bonkers contracts and visualize their temporal characteristics. To gain insights into the purpose of these smart contracts we perform a basic analysis of code and message content including deployment code. We consider data up to Ethereum block 6900000 (end of 2018).","PeriodicalId":302776,"journal":{"name":"Proceedings of the Third ACM Workshop on Blockchains, Cryptocurrencies and Contracts","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128183712","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Proceedings of the Third ACM Workshop on Blockchains, Cryptocurrencies and Contracts","authors":"","doi":"10.1145/3327959","DOIUrl":"https://doi.org/10.1145/3327959","url":null,"abstract":"","PeriodicalId":302776,"journal":{"name":"Proceedings of the Third ACM Workshop on Blockchains, Cryptocurrencies and Contracts","volume":"73 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131469687","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}