CLUE: Towards Discovering Locked Cryptocurrencies in Ethereum
This work identifies a significant financial loss problem for Ethereum users by quantifying and categorizing permanently locked cryptocurrencies.
This paper investigates locked cryptocurrencies in Ethereum, defining three categories of accounts where funds are inaccessible. Their tool, CLUE, identified over $216 million in locked cryptocurrencies and analyzed the underlying reasons.
As the most popular blockchain that supports smart contracts, there are already more than 296 thousand kinds of cryptocurrencies built on Ethereum. However, not all cryptocurrencies can be controlled by users. For example, some money is permanently locked in wallets' accounts due to attacks. In this paper, we conduct the first systematic investigation on locked cryptocurrencies in Ethereum. In particular, we define three categories of accounts with locked cryptocurrencies and develop a novel tool named CLUE to discover them. Results show that there are more than 216 million dollars value of cryptocurrencies locked in Ethereum. We also analyze the reasons (i.e., attacks/behaviors) why cryptocurrencies are locked. Because the locked cryptocurrencies can never be controlled by users, avoid interacting with the accounts discovered by CLUE and repeating the same mistakes again can help users to save money.