Proof Crater — Privacy-Preserving State Commitment Engine

Overview

Proof Crater is a trust-minimized platform for anchoring and verifying blockchain state. It combines Zero-Knowledge (ZK) Proofs and Merkle Tree commitments to enable secure, private, and tamper-evident data interactions.

The system serves two primary functions:
1. ZK-Vaults for anonymous, non-custodial asset distribution (salaries, airdrops, rewards);
2. Snapshot Registries for verifiable historical records.
By committing cryptographic roots on-chain, Proof Crater ensures that complex off-chain datasets can be verified later without trusting the original data provider, infrastructure, or exposing sensitive user identities.

Problem

Modern decentralized finance and governance face a dual challenge of privacy and transparency:

• Privacy Leakage: Standard distributions (airdrops, payroll) link sender and receiver addresses, creating permanent, deanonymized financial footprints.
• Fragile Evidence: Historical audits and governance votes often rely on centralized APIs or recomputed data that is expensive to verify and difficult to defend months after the event.
• Centralization Risks: Most "verified" claims still require trusting an intermediary's database or a specific service provider's availability.

Solution

Proof Crater introduces a unified primitive for private and verifiable state claims:

1. ZK Anonymous Distribution (The ZK Vault)

1. Commitment: A depositor creates a list of private obligations (receiver + amount), builds a Merkle tree, and locks funds in a ZK Vault contract alongside the Merkle root.
2. Browser-Side Proving: The recipient generates a ZK-SNARK and a Merkle proof locally in their browser. No private keys or secrets ever leave the user's device.
3. Relayed Withdrawal: A relayer submits the proof and the user's destination address to the contract. The relayer provides the necessary "gas dust" so the user can move funds anonymously.
4. Privacy: The link between the depositor and the recipient is cryptographically severed.

2. Verifiable Snapshots

1. Evidence Anchoring: Off-chain state (block headers, balances, contract state) is compressed into a Merkle root and published on-chain.
2. Independent Verification: Any party can later verify a specific data point using a compact Merkle proof, ensuring the data is identical to what was committed at the time of the snapshot.

Architecture

• ZK Vault & Registry Contracts
  • Immutable EVM contracts that store Merkle roots and manage locked assets.
  • On-chain ZK-SNARK verification logic for anonymous withdrawals.
  • On-chain Merkle proof verification for snapshot data.
• Client-Side Proving Suite
  • Browser-based WASM circuits for generating Zero-Knowledge proofs.
  • Local Merkle proof generation to maintain user sovereignty.
• Relayer Network
  • Facilitates gas-less withdrawals for users to preserve privacy.
  • Prevents the "initial gas" link that typically deanonymizes new wallets.
• Off-chain Indexing
  • Snapshot aggregators and query services for audit-ready historical data.

Security Model

• Non-Custodial: Proof Crater never has access to funds; they are controlled by the smart contract and unlocked only by valid cryptographic proofs.
• Zero-Knowledge: Neither the platform nor the relayer can see the identity of the recipient or the specific commitment being claimed.
• Deterministic: Verification relies solely on the on-chain root and cryptographic math, not the availability of Proof Crater's backend.

Economic Model & Fees

• Upfront Fee Structure: A protocol fee (determined as a percentage of the total deposit) is calculated and subtracted by the smart contract at the moment of deposit.
• Immutability of Claims: Because the fee is settled prior to the confirmation of the deposit, the remaining funds in the ZK Vault are locked and dedicated solely to the recipients. No further subtractions or administrative fees can be applied once the deposit is active.
• Non-Custodial Revenue: Fees are handled programmatically by the smart contract, ensuring the platform never has manual access to user principal.

Use Cases

• Private Payroll & Airdrops: Distribute funds to employees or users without revealing their wallet addresses to the public.
• Anonymous Reward Distribution: Incentivize contributors while maintaining their financial privacy.
• Audit & Compliance: Provide tamper-evident evidence of historical blockchain state for regulators or internal audits.
• Governance Snapshots: Prove eligibility and voting power at a specific block without relying on centralized explorers.

Status

• Core Engine: Smart contracts for Merkle registries and ZK Vaults are operational.
• Privacy Suite: Browser-based proof generation and relayer integration are live.
• Accessibility: Web UI available for both creating private distributions and browsing historical snapshots.