Wraith

A full-privacy platform on Stellar. Bridge assets into a shielded layer, hold private multi-asset balances, send confidential payments, and trade on a zero-knowledge dark pool — all verified on-chain by Soroban smart contracts.

Submission for Stellar Hacks: Real-World ZK.

Deployed on Stellar Testnet

The full system is live and the private round-trip is verified on-chain. Pool: CD7EF4GG32IPVS2PGD2LMXEO3TPEWBZRUCBBSPXQ236CD6TMF5S4UUZR (wired to 5 UltraHonk verifiers). Proven end-to-end:

All six flows are verified live on testnet, each gated by a real Noir/UltraHonk proof checked inside the Soroban contract:

• Bridge — deposit (root matches the SDK byte-for-byte) and withdraw with a real ZK proof (tx).
• Pay — a 2-in/2-out shielded transfer, amounts hidden, value conserved in-circuit (tx).
• Swap — hidden orders placed, matched at the midpoint (tx), and cancelled with refund (tx).
• Soundness: a tampered proof and a replayed nullifier are both rejected on-chain.

See DEPLOYMENT.md for every transaction.

Full contract IDs, transactions, and a one-command reproduction are in DEPLOYMENT.md.

Trustless cross-chain bridge — Ethereum → Stellar (verified live)

The Bridge is a genuine trust-minimized cross-chain bridge, not a relayer: assets locked on Ethereum Sepolia arrive as shielded notes on Stellar, with provenance proven on-chain. The full loop is verified live (no trusted relayer):

1. Lock 0.001 ETH on Sepolia (WraithBridgeL1 0xcF40c553…).
2. An Ethereum sync-committee BLS signature is verified natively on Soroban (EthLightClient), recording a real Ethereum execution state_root on Stellar — the same trust model as Helios, but with no SNARK-wrap because Stellar has native BLS12-381 (the check is ~30M of the 100M budget, vs ~80M gas on the EVM).
3. bridge_in proves the lock with an in-contract Merkle-Patricia storage proof against that state_root and mints a shielded note (tx 4b3760d1…, SUCCESS).

This is the hackathon's "wild" idea — a cross-chain private bridge using Stellar's BN254/BLS12-381 compatibility to verify another chain's consensus. Full evidence + reproduction in BRIDGE_DEPLOYMENT.md; design in BRIDGE_SPEC.md.

Modules

Module	Description
Bridge	Move classic Stellar assets (XLM, USDC, …) in/out of Wraith via the Stellar Asset Contract.
Portfolio	View and manage shielded, multi-asset balances.
Pay	Send private payments — amounts and participants hidden.
Swap	Dark-pool DEX — hidden orders, ZK-proven fair matching, atomic settlement.

How the ZK is load-bearing

Every state transition out of the shielded layer (withdraw, transfer, place/cancel order, match) is gated by an UltraHonk (Noir) zero-knowledge proof verified inside a Soroban contract. Without a valid proof, no funds move. Privacy comes from the circuit design (hidden inputs), and integrity from on-chain verification of BN254 / Poseidon2 — the primitives Stellar shipped in Protocol 25–26.

Repository layout

circuits/noir/   Noir circuits (withdraw, transfer, place_order, match_orders, cancel_order)
contracts/       Soroban smart contracts (wraith-pool + UltraHonk verifier integration)
sdk/             TypeScript client library (notes, proofs, Merkle tree, tx building)
matcher/         Off-chain order-matching service
frontend/        React app (Bridge / Portfolio / Pay / Swap)
vendor/          Reference repos (rs-soroban-ultrahonk, noir-poseidon) — gitignored
SPEC.md          Full technical specification
SHARED.md        Cross-component invariants (crypto params, encodings) — source of truth
TOOLCHAIN.md     Pinned tool versions and install steps

Quick start

source ./env.sh        # put nargo / bb / stellar on PATH
# circuits
cd circuits/noir/withdraw && nargo test
# contracts
cd contracts && cargo build --target wasm32-unknown-unknown --release
# sdk / frontend
pnpm install && pnpm -r build

See SPEC.md for the full design and TOOLCHAIN.md for setup.

Status

Hackathon work-in-progress. Built on Stellar testnet. Components marked as MVP / mock in their READMEs where applicable.