CHIPs · CHIP-2021-07 · draft
UTXO Fastsync
Proposes a way for nodes to create, share, check and load UTXO-set snapshots over the P2P network, so new nodes can sync in hours instead of replaying the whole chain.
Summary
This proposal “defines a method for nodes to generate, distribute, validate, and consume UTXO snapshots via the BCH P2P network.” A new node could download a snapshot of the current UTXO set instead of processing every block since 2009.
It is a peer-services proposal. It does not ask miners to commit to UTXO sets at this time, but it “paves the way to UTXO commitments in the future if desired.”
Motivation
- Faster setup: the CHIP says new nodes could join “within a couple of hours (or less), instead of the current average of 8+ hours.”
- Long-term scaling: combined with block pruning, snapshots let BCH keep node costs manageable as the chain grows from gigabytes to terabytes.
What it specifies
How nodes generate snapshots, how peers advertise and transfer them, and how a receiving node validates one before using it. The original post is the specification (version 0.1.1, July 2021).
Current status
Draft. Discussion was still active in 2026, including ideas around zero-knowledge proofs for UTXO commitments. The “2027 protocol upgrade ideas” thread notes a general view that UTXO commitments do not require consensus changes. No formal stakeholder statements were found.