# Outbreaker Technical Overview

Outbreaker is privacy infrastructure for tokenized assets on Robinhood Chain mainnet (Chain ID 4663). Its design combines registry-verified assets, shielded note commitments, client-local key material, readiness-gated Groth16 proofs, nullifier-based double-spend prevention, validated swap quotes, and bounded selective disclosure.

## Core mechanism

1. A user connects a wallet and selects an asset that the on-chain Registry marks as supported.
2. A shield transaction deposits the asset into the Pool. Native ETH enters through the Native Gateway.
3. The client creates private note material locally and submits only the commitment required by the protocol.
4. For a private transfer or withdrawal, the client creates a witness from local note data and can generate a Groth16 proof when signed proof artifacts and the deployed verifier are ready.
5. The contract verifies the proof and records a unique nullifier. Reusing an existing nullifier is rejected, preventing the same note from being spent twice.
6. A successful private transfer creates new note commitments. A successful withdrawal releases the corresponding asset to the selected destination.

## Privacy boundary

Private note secrets, spending keys, notes, and transfer or withdrawal witnesses remain on the user's device. The local notes wallet encrypts stored material with AES-256-GCM and derives its encryption key with PBKDF2-SHA256 using 310,000 iterations.

Outbreaker does not claim that every part of a blockchain transaction is hidden. Deposits, commitments, nullifier-related information, execution parameters, network metadata, transaction timing, and current swap inputs may remain public. Current swap asset pairs and amounts are plaintext API inputs. Signed selective disclosure shares chosen claims without exporting note secrets, but it is not a zero-knowledge disclosure proof.

## Runtime safety

The application checks chain identity, deployed contract bytecode, supported-asset registry state, proof-artifact readiness, swap quote integrity, amount bounds, quote expiry, slippage limits, calldata integrity, and required supporting services before enabling relevant actions. Unsupported or unready capabilities remain blocked rather than falling back to simulated transactions.

## Official contracts

- Registry: `0xccBF81a06Ba52561B14E8481Db7E5899D743EbE3`
- Pool: `0x03CC459a5085432a44edbE3C009d28962a0191dD`
- Settlement: `0xAdE3363c67F8D1a78515160799d1044758aacDA9`
- Native Gateway: `0x20ff139048B169C4ed4F7C6a0aEE9f717b09495F`

Verify contracts independently on the [Robinhood Chain Blockscout explorer](https://robinhoodchain.blockscout.com/).