Chain-Based Consensus (Longest Chain Rule)
Also known as: Longest Chain Rule, Work-Based Consensus, Chain Selection
A consensus approach where the chain with the most accumulated work or stake is considered the valid blockchain.
Chain-based consensus is a method used in blockchains like Bitcoin and Ethereum (pre-Merge) where the network agrees on the chain with the highest accumulated difficulty or stake. This approach resolves forks by choosing the 'longest chain'—the one with the most computational work (Proof of Work) or most validator support (Proof of Stake). It simplifies consensus and ensures deterministic finality over time. While robust against simple forks, it can be vulnerable to 51% attacks if a single actor controls the majority of mining or staking power.