pq-devnet-4 · in progress

Consensus
written to be read.

gean is a Go consensus client for Lean Ethereum, built around the idea that protocol simplicity is a security property — readable, auditable, verifiable end-to-end.

View on GitHub Read the rationale

82+ stargazers

MIT license

Go 1.22

gean ~ node-0main · 4edcf7b

$ make build
$ ./bin/gean \
    --genesis config.yaml \
    --bootnodes nodes.yaml \
    --validator-keys keys \
    --node-id node0

[info] gean started. listening on :9000
[info] ENR · 0xa4f…b2c · peers 12
[ok]   finalized slot 2,418,021 in 3.2s▍

— Capabilities

Built for security, designed for developers.

Commitments expressed in the codebase you can read today — not a roadmap of intentions. Each is a constraint we hold ourselves to.

01
Post-Quantum Signatures
Post-quantum signature scheme — cryptographic security against quantum threats.
02
Sub-Second Finality
3SF-mini for finality and LMD GHOST as fork-choice algorithm — finality in seconds.
03
Checkpoint Sync
Checkpoint sync, attestation subnets, and an optional aggregator role.
04
Persistent Storage
Pebble DB for fast, durable state persistence.
05
Cross-Client Interop
Tested against zeam, ream, lantern, and ethlambda via lean-quickstart.

— Philosophy

Protocol simplicity is a security property.

A consensus client should be something a developer can read, understand, and verify without trusting a small class of experts. If you can’t inspect it end-to-end, it’s not fully yours.

Read the source

01
Readable over clever
Code is written so someone unfamiliar with the codebase can follow it. Naming is explicit. Control flow is linear where possible.
02
Minimal dependencies
Fewer imports means fewer things to break, audit, and understand.
03
No premature abstraction
Interfaces and generics are introduced when the duplication is real, not when it is hypothetical. Concrete types until proven otherwise.
04
Flat and direct
Avoid deep package hierarchies and layers of indirection. A function should do what its name says, and you should find it quickly.
05
Concurrency only where necessary
Go makes concurrency easy to write and hard to reason about. We use it at the boundaries and keep the core logic sequential and deterministic.

— Current status

PQ Interop · devnet progress

Working on pq-devnet-4 · next pq-devnet-5

History

Oct 2025

pq-devnet-0Completed

leanSpec@4b750f2

Multi-client devnet harness
Bootstrap multi-client devnet harness and baseline tooling
Baseline interop trials
4s slots, QUIC, Gossipsub v1.0 — initial interop sweep
Apply modified 3SF-mini consensus
Wire up 3SF-mini fork-choice & finality variant

Dec 2025

pq-devnet-1Completed

leanSpec@050fa4a, leanSig@f10dcbe

Consensus envelope pipeline
SignedAttestation, SignedBlockWithAttestation, proposer-attestation ordering, signed storage/sync path
XMSS/leanSig integration
CGo bindings, key management, signing, verification
Baseline PQ performance metrics
Initial measurements for PQ signing & verification cost
Cross-client interop
Multi-client devnet compatibility testing

Jan 2026

pq-devnet-2Completed

leanSpec@4edcf7b, leanSig@73bedc2, leanMultisig@e447413

Consensus envelope pipeline
SignedAttestation, SignedBlockWithAttestation, proposer-attestation ordering, signed storage/sync path
XMSS / leanSig / leanMultisig integration
CGo bindings, key management, signing, verification, signature aggregation
Persistent storage
Pebble-backed persistent storage layer
PQ aggregation performance
Baseline performance metrics for PQ signature aggregation

Feb 2026

pq-devnet-3Completed

leanSpec@TBD, leanSig@TBD, leanMultisig@TBD

Aggregator role decoupling
Separate aggregator role from block production, new is_aggregator ENR field, validator-config.yaml updates
Attestation subnet networking
attestation_{subnet_id} gossipsub topic, aggregation gossipsub topic, subnet assignment by validator_id % subnets_count
Aggregated signature propagation
Aggregators collect and aggregate attestations, propagate to aggregation topic, proposer includes aggregates in blocks
Slot interval restructuring
5 intervals × 800ms (build & propagate, attest, aggregate, update safe target, accept attestations)
Cross-client interop
Multi-client devnet with 5 initial validators (1 per client), north star target of 128 validators

Active

pq-devnet-4Active

leanSpec@TBD, leanSig@TBD, leanMultisig@TBD

Recursive PQ signature aggregation
Enable recursive PQ signature aggregation using leanVm for efficient proof composition
Aggregate coalescing
Coalesce multiple aggregates for the same message into one final aggregate
Single aggregate per message in blocks
Ensure blocks contain a single aggregate per message instead of multiple aggregates

Planned

pq-devnet-5Planned

Block-level proof aggregation
Aggregate all block proofs — including the block signature — into a single block-level proof to reduce overall block size
Goldfish underlay fork-choice
Replace 3SF-mini with Goldfish as the underlay fork-choice protocol, including Goldfish vote production and propagation
Multi-message aggregation (Type 1 & Type 2)
Type 1 — single-message, single-slot recursive aggregation; Type 2 — aggregation across distinct (message, slot) pairs
Deterministic committee selection
committee(slot) = proposer_validator(slot) + next N validators, derived from the proposer index per slot
Delayed Goldfish vote inclusion
Slot s — committee signs votes; s+1 — votes drive fork choice; s+2 — aggregates included in the block
Depth-based placeholder finality
Ship a naïve depth-based finality rule as a temporary placeholder, then iterate toward a proper overlay finality gadget