Documentation

Introduction

Cipher is an open privacy Layer 2 for Base, validated on commodity hardware.

What is Cipher?

Cipher is an open privacy Layer 2 for Base. ETH bridges into a shielded pool, transfers move privately inside it, and withdrawals settle back to Base — anchored by Groth16 zero-knowledge proofs over BLS12-381. The validator set is designed for commodity hardware: laptops, home PCs and single-board computers running a verify-only role.

The on-chain settlement contract holds the pool merkle root, the nullifier set and the validator registry — replay protection and validator stake are enforced on Base itself.

Two primitives

Private payments

Shielded pool with Groth16 proofs. Range-proven u64 values, Poseidon commitments, expiration-bound withdrawals.

Private compute (alpha)

WASM jobs verified by the same BFT cohort. Encrypted I/O via AES-256-GCM and ownership-proof bound output notes.

Why commodity hardware?

A Groth16 proof verifies in roughly ten milliseconds on a single CPU core. Validators are verify-only — proof generation stays with the user. Any laptop, server-room leftover or single-board computer can carry the role. No GPUs, no specialised silicon, no co-location.

Economic model

Withdrawal fees do not flow to a founder account. They are credited on-chain to the validator that led verification, in the ValidatorAccount.pending_rewards field. Validators pull their earnings out via claim_rewards. There is no founder cut to remove.

The four on-chain instructions that wire the loop:

register_validator — anyone meeting MIN_VALIDATOR_STAKE joins the set
distribute_fee — credits pending_rewards on the leader's account
claim_rewards — validator withdraws accumulated earnings
slash_validator — burns 1–100% of stake for protocol violations

What's anchored on Base

Base bridge

BridgeState.merkle_root, nullifier records, replay protection via expiration_slot — all enforced by the on-chain contract.

Validator registry

Validator registration, minimum stake, reputation tracking, slashing for equivocation and persistent unavailability.

BFT consensus

7-of-10 default threshold, configurable per network. Reputation-gated voting; slashing evidence recorded in protocol.

MPC trusted setup

BGM17 phase-2 ceremony with a verifiable transcript. Mainnet activation gates on its completion.

Status

v0.5.0-rc5 — pre-mainnet. Audit pending. MPC ceremony in progress.

Metric	Value
Lines of Rust	~33,000
Tests passing	407
Commits	246
Proof verify time	~10 ms / proof
Proof size	192 bytes
Default BFT threshold	7 of 10
Coordinator HA	active / passive failover, < 30s RTO
License	MIT

Where to go next

Quick start — get a node running on devnet
Architecture — system layers and module structure
Validator guide — run a validator on a laptop
MPC ceremony — contribute to the trusted setup
Base bridge — on-chain contract reference

Vision