Block and Transaction Delivery in Ethereum Network

Abstract

We present a comprehensive analytical model for block and transaction distribution in the Ethereum P2P network. We model the data distribution protocol in which a node forwards a full block (transaction) to some of its peers and its hash to others, and combine this model with the connectivity and transmission models to obtain input and output data rates, which are then fed into a priority M/G/1 Jackson network queuing system in which blocks are given preference over transactions, and transactions are further grouped into two priority classes according to gasprice. Block and transaction delivery times are found to be mainly determined by node connectivity and network size, and prioritization provides faster service for higher priority transactions. We also model an Eclipse-like attack that degrades data delivery times and block finalization time, i.e., the time for a block to be officially confirmed, by reducing network connectivity, and show that its impact can be countered by adjusting the portion of peers which receive a full block. Lastly, we determine the probability of uncle blocks being included in the longer chain and demonstrate how the Eclipse attack affects this probability.