Vitalik: FOCIL and EIP-8141 can work together to achieve censorship-resistant fast on-chain

Vitalik Buterin posted on the X platform that there is an important synergy between the FOCIL mechanism and the account abstraction proposal Ethereum's EIP-8141 (based on 7701). EIP-8141 elevates smart accounts (including multi-signature, quantum-resistant signatures, key changes, Gas sponsorship, etc.) to "first-class citizens," meaning that operations from these accounts can be directly packaged as on-chain transactions without additional encapsulation. At the same time, privacy protocols can achieve multi-tenant account models through paymaster or 2D nonce mechanisms, thus gaining the same level of native support. FOCIL provides a censorship-resistant fast transaction inclusion mechanism. With the combination of both, various transactions, including smart wallet transactions, Gas sponsorship transactions, and privacy protocol transactions, can be included in blocks by one of the 17 roles (proposers or includers) randomly selected for each time slot.

Vitalik stated that this design can ensure that transactions are almost guaranteed to be completed on-chain within 1-2 time slots in adversarial environments. In the current version, each FOCIL unit is approximately 8kB, which is relatively small, but there is a potential for expansion in the future, allowing most transactions in a block to enter through the FOCIL channel. This architecture is similar in characteristics to the multi-parallel proposer (MCP) design, but the difference is that FOCIL does not control the "last look" related to MEV; this role is still allocated through the ePBS auction mechanism.

Vitalik emphasized that even if 100% of the block time slots are monopolized by adversarial parties through the proposer-builder separation (PBS) mechanism, refusing to connect to the public mempool or discriminating against specific applications, FOCIL can still ensure that all transactions receive fast inclusion. Although this design does not eliminate the centralization risk of the proposer role, it significantly weakens its power. Under the EIP-8141 framework, transactions from smart wallets or privacy protocols can be directly received by FOCIL includers through the public mempool, without the need for additional intermediaries or encapsulation processes. Vitalik concluded that Ethereum is accelerating the advancement of its core architecture upgrades.