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arXiv · 2601.03862

Majorum: Ebb-and-Flow Consensus with Dynamic Quorums

Francesco D'Amato·Roberto Saltini·Thanh-Hai Tran·Yann Vonlanthen·Luca Zanolini
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Abstract

Dynamic availability is the ability of a consensus protocol to remain live despite honest participants going offline and later rejoining. A well-known limitation is that dynamically available protocols, on their own, cannot provide strong safety guarantees during network partitions or extended asynchrony. Ebb-and-flow protocols [SP21] address this by combining a dynamically available protocol with a partially synchronous finality protocol that irrevocably finalizes a prefix. We present Majorum, an ebb-and-flow construction whose dynamically available component builds on a quorum-based protocol (TOB-SVD). Under optimistic conditions, Majorum finalizes blocks in as few as three slots while requiring only a single voting phase per slot. In particular, when conditions remain favourable, each slot finalizes the next block extending the previously finalized one.

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Francesco D'Amato, Roberto Saltini, Thanh-Hai Tran, Yann Vonlanthen, Luca Zanolini. 2026-01-07. Majorum: Ebb-and-Flow Consensus with Dynamic Quorums. https://arxiv.org/abs/2601.03862

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