Shutter Network’s ‘Holy Trinity’ Fix Aims to Slash Ethereum’s Censorship Woes

Ethereum’s creeping centralization problem just got a potential lifeline—or at least a band-aid. Shutter Network is pitching a three-pronged defense it’s calling the ‘Holy Trinity’ to combat transaction censorship and validator dominance.

The proposal? A mix of decentralized sequencing, encrypted mempools, and forced execution fairness. It’s the kind of tech jargon that makes crypto true believers salivate—and Wall Street roll its eyes. Because nothing says ‘decentralized utopia’ like needing a holy trinity to fix your holy mess.

Will it work? Maybe. But until then, Ethereum’s ‘uncensorable’ ledger keeps looking more like a permissioned playground for the MEV cartel.

The Three-Part Proposal: 

Out-of-protocol PBS currently relies on relays to mediate between proposers and builders, making them centralized choke points. In this system, relays receive blocks from builders and forward headers to proposers, who then sign and return the selected header. While effective, it introduces trust and censorship risks.

Enshrined PBS  proposes removing these intermediaries by implementing PBS directly in Ethereum’s consensus layer. Builders submit a hash of the block payload; if the beacon block referencing it gains enough attestations, the payload is released, and validators confirm it was delivered on time. However, ePBS doesn’t resolve builder centralization or malicious MEV extraction – hence the need for the next two components.

EIP-7805 introduced the concept of FOCIL, where validators select an Inclusion List (IL) committee per slot. Each member of the IL committee  compiles a list of pending transactions from the public mempool, which are then merged and must be included in the block by the proposer. Attesters only validate blocks that comply.

This system ensures censored transactions still have a guaranteed path to inclusion, assuming at least one honest IL committee member. It enforces accountability at the block production level and makes censorship visible and punishable.

3. Encrypted Mempools: Leveling the Playing Field

Encrypted mempools prevent frontrunning and MEV extraction by hiding transaction contents until block inclusion is confirmed. Highlighted by Vitalik Buterin as a key future upgrade, this system creates fairness by keeping transaction data private until it’s too late for manipulators to exploit.

Shutter recently proposed a practical roadmap for a threshold encrypted mempool on Ethereum L1, leveraging Shutter and proposer commitments to make this system viable within Ethereum’s current architecture. Shutter has already deployed its encrypted mempool on the Gnosis Chain using a threshold encryption scheme and has proposed a phased path to Ethereum mainnet integration.

A Coordinated Execution Model

In a network using ePBS, FOCIL, and encrypted mempools, users submit encrypted transactions to the public mempool. The IL committee selects transactions for mandatory inclusion. The mempool provider then releases the necessary decryption material, which upon receiving sufficient attestations are used by the Builder for decryption.If valid transactions are omitted despite available gas, the block is invalid. If decryption is delayed, transactions roll into the next slot—ensuring inclusion, privacy, and fairness even in adversarial conditions.

Shutter outlined the potential transaction FLOW in a network that implements ePBS, FOCIL, and an encrypted mempool:

Users submit encrypted transactions using a public key from the mempool provider. An IL committee monitors the mempool and builds inclusion lists, which the proposer merges into a single list. The builder must include these transactions in the next block or risk the block being invalidated if gas remains.

Once decryption material is released and attested by a two-thirds supermajority of attesters, the builder decrypts and places the transactions at the top of the block to prevent MEV abuse. If the decryption material isn’t sufficiently attested, the transactions are deferred to the next IL. The proposer includes the final block via ePBS, but failure to include valid IL transactions can result in slashing or rejection.

Ethereum faces a growing censorship problem that threatens its Core principles of decentralization and neutrality. The Holy Trinity of Censorship Resistance, consisting of ePBS, FOCIL and encrypted mempools, presents a comprehensive solution that could restore Ethereum’s foundational values. As the network continues to evolve toward becoming a global settlement layer, implementing these measures will be crucial to ensuring that Ethereum remains true to the vision outlined in its whitepaper: a credibly neutral, decentralized platform accessible to all.