Mayflies, breeders, and busy bees in ethereum: Smart contracts over time

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 6 900 000 (end of 2018).