Two central design goals for blockchain protocols are maximizing censorship resistance and minimizing latency. These goals are in tension: Censorship resistance requires additional rounds of communication, while low latency requires minimizing communication rounds. This tradeoff is especially acute if blockchains are to support efficient onchain markets: Market participants need both low latency and robust protection against proposer censorship.
The resolution is that censorship resistance does add protocol rounds, but it reduces the latency users experience when they require censorship-resistant inclusion.
One line of work focuses on adding strong censorship-resistance guarantees to blockchain protocols. For example, Ethereum is considering FOCIL / EIP-7805, and Solana is considering Constellation (also see MCP). Both are based on a simple two-round inclusion-list idea: before a block is proposed, validators collect transactions that the next block is not allowed to ignore. Similar proposals are being considered across the blockchain ecosystem.
Another line of work focuses on reducing latency to the minimum possible. Formally, this is measured by good-case latency: how quickly a blockchain can commit a block when the proposer is honest and the network is well-behaved. Our recent analysis shows that, in standard Byzantine Fault Tolerant (BFT) consensus, 3 rounds is the minimum when more than one-fifth of validators may be faulty. Most production protocols are designed for a stronger fault model, usually up to n/3 faulty validators.
