# Protocol Berg v2: Alejandro Ranchal-Pedrosa - Rebased Rollups

- Channel: [ETHBerlin](https://streameth.org/ethberlin)
- Date: 2025-10-09
- Duration: 23:45
- Topics: Protocol Berg, Berlin, Conference, Blockchain, Protocol, Web3, Decentralization, P2P
- Watch: https://streameth.org/watch/yt-DOv6zqMAt_I
- YouTube: https://www.youtube.com/watch?v=DOv6zqMAt_I

## Description

Rebased rollups introduce a novel paradigm blending the advantages of based and non-based rollups to provide synchronous composability, credible neutrality, and reduced latency without incurring the full cost and latency penalties associated with Ethereum-based rollups. By becoming "based on-demand" for durations shorter than a full Ethereum slot, rebased rollups efficiently utilize Ethereum’s existing proposer set to facilitate faster transaction confirmations and increased throughput.

This presentation explores the technical challenges posed by current Layer 2 (L2) rollups, particularly fragmentation and loss of synchronous composability, and analyzes existing solutions including mesh and hub-based approaches, highlighting their limitations concerning credible neutrality and economic security. We present rebased rollups as a practical solution, detailing their architecture, security trade-offs, and mechanisms such as preconfirmations and dynamic attestation tracking.

We conclude by outlining how rebased rollups horizontally scale economic security and transaction throughput, providing Ethereum-aligned synchronous composability with latency comparable to centralized sequencers, ultimately balancing decentralization, neutrality, performance, and cost-effectiveness for the broader Ethereum ecosystem.

Protocol Berg v2
12-13 June 2025
Berlin
https://v2.protocol.berlin