Challenges in decentralized name management: the case of ENS

DNS has often been criticized for inherent design flaws, which make the system vulnerable to attack. Further, domain names are not fully controlled by users, meaning that they can easily be taken down by authorities and registrars. Due to this, there have been efforts to build a decentralized name service that gives greater control to domain owners. The Ethereum Name Service (ENS) is a major example. Yet, no existing work has systematically studied this emerging system, particularly regarding security and misbehavior. To address this gap, we present the first large-scale measurement study of ENS. Our findings suggest that ENS has shown growth during its four years' evolution. We identify several security issues, including traditional name system problems, as well as new issues introduced by the unique properties of ENS. We find that attackers are abusing the system with thousands of squatting ENS names, a number of scam blockchain addresses and indexing of malicious websites. We further develop a new record persistence attack, to find that 22,716 .eth names (3.7% of all names) are vulnerable to name hijacking. Our exploration suggests that our community should invest more effort into the detection and mitigation of issues in decentralized name services.