Ethereum Ancestry Prover

An all-in-one solution for proving that a beacon block is a predecessor of another beacon block.

Currently, the proof is derived only from the block_roots beacon state property, thus the target block cannot be older than SLOTS_PER_HISTORICAL_ROOT (8192 blocks, ~27 hours). Support for older blocks is planned.

Providers

The library makes use of proof providers, which are responsible for fetching the necessary data from the Ethereum chain, and generating the proofs.

Supported providers are:

• LodestarProvider: which uses the amazing Lodestar beacon node.
• StateProverProvider: which uses state prover to interact with the Lodestar API. Useful for generating single merkle proofs.

Usage

use ancestry_prover::{AncestryProver, LodestarProvider, verify};

let prover_api = LodestarProvider::new("https://lodestar-mainnet.chainsafe.io".to_string());

// Alternatively, you can use the StateProverProvider
// or a custom provider that implements the ProverProvider trait.
// let prover_api = StateProverProvider::new(
//     "mainnet".to_string(),
//     "http://127.0.0.1:3000".to_string(),
// );

let prover = AncestryProver::new(prover_api);

// This is the block slot that we want to prove
let target_block_slot = 8942024;

let recent_block_slot = 8942159;
let recent_block_state_id =
    "0xca0ad12cf0a4d5935c1636a88bc7d22ccacc86637f406e799f3b20d22ca715f8";

let proof = prover
    .prove(target_block_slot, recent_block_slot, recent_block_state_id)
    .await
    .unwrap();

assert!(verify(
    &proof,
    target_block_slot,
    recent_block_slot,
    recent_block_state_id,
));

Acknowledgements

• @ralexstokes for his amazing work on the ethereum-consensus and ssz_rs libraries.
• Lodestar team for their amazing work on the Lodestar beacon node.
• axelar-light-client team for setting the foundation for this project.