Deciphering Cryptocurrencies by Reverse Analyzing on Smart Contracts

As the initial application of blockchain, Bitcoin is the most famous blockchain application as cryptocurrency and it has led to a misconception that blockchain can only be used to issue cryptocurrency. Meanwhile, the growing number of companies and organizations issuing their own cryptocurrencies based on blockchain has led to more confirmation that the main role of blockchain is to be used to issue cryptocurrency. However, blockchain is originally intended to achieve decentralized application, and cryptocurrency is just a byproduct of it. In this paper, we figured out how many smart contracts on Ethereum are involved issuing cryptocurrency, how many people are using these smart contracts and what is the revenue status of these smart contracts. To address these question, we collect more than 140,000 open source smart contracts and 16 million closed source smart contracts from Ethereum, and then identify the smart contracts that involve issuing cryptocurrency (called IC-contract) by determining whether the contract implements ERC20 standard. For the closed source smart contracts, we propose a reverse hash mapping method to determine the IC-contract at bytecode level. Additionally, we also obtain the transactions of all the IC-contracts and find that the open source IC-contracts have more users. Analyzing the IC-contracts based on transactions reveals that most of the IC-contracts have exceptionally low user activity, but most of them are profitable actually.