AMP: Arc Multi-Proposer Protocol with Bounded Inclusion Guarantees

2026-05-22

AI Summary

This work addresses the issues of monopolistic transaction inclusion and ordering by individual validators and the lack of anti-front-running safeguards in blockchain systems. Building upon the Tendermint consensus protocol, it introduces a multi-proposer mechanism that decouples transaction dissemination from consensus. By employing dedicated proposer nodes to broadcast transaction payloads, an architecture without a traditional mempool, public acknowledgments, and coordinated multi-proposer interaction, the protocol achieves batch finality of payloads. The design innovatively incorporates bounded inclusion guarantees and a deterministic ordering algorithm, eliminating single-point control and ensuring that any transaction confirmed by all correct nodes is guaranteed inclusion in the next block. This approach effectively curbs validator manipulation while enhancing throughput and achieving decentralized, fair transaction inclusion and ordering.

Abstract

Blockchain systems that settle financial transactions face a structural tension: the single validator that assembles each block holds unilateral power over transaction inclusion and ordering. Traditional markets curb this very power through front-running and market-manipulation laws. Regulators have flagged the absence of such rules as a first-order concern for blockchain-based financial infrastructure. In response, we introduce AMP, a multi-proposer protocol, on top of the Tendermint consensus algorithm, where no validator can control the flow of transactions into blocks. Instead, dedicated nodes called proposers sit between users and validators. They collect user transactions, group them into payloads, and broadcast the payloads to all validators. Consequently, there is no mempool, and AMP applies the design principle of separating dissemination from agreement, which can lead to higher throughput. Validators publicly attest to receiving payloads and run consensus to decide the set of payloads to include in the next block. When all correct validators attest to a given payload, AMP guarantees that payload will be included in the next block; a block thus contains payloads from multiple proposers, allowing for bulk finalization. This bounded inclusion guarantee along with a deterministic ordering algorithm which is run over all payloads included in a block, curbs the power of any single validator. Validators no longer control what is included in a block, nor can they arbitrarily order the contents of blocks.

Problem

• transaction inclusion
• blockchain regulation
• front-running
• market manipulation
• validator control

Innovation

• multi-proposer protocol
• bounded inclusion guarantee
• transaction ordering fairness
• separation of dissemination and agreement
• Tendermint consensus