Privacy-preserving DeFi protocol demonstrating real PVM integration on Polkadot Hub

Track 2 Submission: PVM Smart Contracts — Blake2b hashing, BN128 Pedersen commitments, and precompile-ready architecture for Sr25519/Ed25519/XCM.

This section maps directly to the judging requirements.

Network:

• Chain ID: 420420417
• RPC: https://eth-rpc-testnet.polkadot.io/
• Explorer: https://blockscout-testnet.polkadot.io/

Contracts:

• CryptoRegistry: 0x237259A349F258eD5d561F90dcb701f4371169B3 — PVM precompile registry
• StealthPayment: 0x98DB1edC0ED10888d559C641F709A364818B0167 — EIP-5564 stealth addresses
• StealthVault: 0x5290EC1961854B8a45346f74BeF775E51d4Ba076 — Commitment-based privacy vault
• OmniShieldEscrow: 0xFa10b866e5B4a3BDD2d0a978FCB5cAbb334372BE — Multi-party escrow
• YieldRouter: 0xa4B00C51eD83c7a9E1F646E9C0329F4E61f651F1 — Cross-chain yield aggregation
• XcmRouter: 0x2BA3337232F5b1eA4b14f3ca0121C3272c25Bb4E — XCM message dispatcher
• OmniShieldHub: 0xCe7917f133B5f31807cC839DCC44f836D8ca7142 — Central coordinator

cd frontend
npm install
npm run dev
# Open http://localhost:3000

Key Pages:

• / — Dashboard with Track 2 banner
• /pvm — PVM Registry & Live Demos (main feature)
• /stealth — Private payment flows
• /scanner — Event monitoring

Hosted frontend: https://omni-shield-zeta.vercel.app/

Hosted backend health endpoint: https://omni-shield.onrender.com/health

cd contracts
forge install
forge test -vv

# Track 2 test suites
forge test --match-path test/Blake2bIntegration.t.sol -vv       # 50+ Blake2b tests
forge test --match-path test/PrecompileArchitecture.t.sol -vv  # Precompile detection
forge test --match-path test/BN128Stealth.t.sol -vv           # Pedersen commitments

Why: Polkadot uses Blake2b for account IDs, storage keys, and merkle trees. Standard EVM only has Keccak256.

Implementation: contracts/src/libraries/PvmBlake2.sol

/// @notice Compute Substrate AccountId from public key
function computeSubstrateAccountId(bytes32 pubkey)
    internal view returns (bytes32 accountId)
{
    return blake2b256(abi.encodePacked(pubkey));
}

/// @notice Blake2_128Concat storage key (Substrate format)
function blake2b128Concat(bytes memory key)
    internal view returns (bytes memory storageKey)
{
    bytes16 hash = blake2b128(key);
    return abi.encodePacked(hash, key);
}

Live Demo: Try /pvm page → Blake2b Hasher

Why: Transaction privacy through amount hiding. Foundation for zero-knowledge proofs.

Implementation: contracts/src/libraries/BN128Stealth.sol

/// @notice Compute Pedersen commitment: C = v*G + r*H
/// @dev Uses BN128 precompiles (ecMul 0x07, ecAdd 0x06)
function computeCommitment(uint256 value, uint256 blindingFactor)
    internal view returns (uint256 cx, uint256 cy)
{
    Point memory vG = pointMul(Point(G_X, G_Y), value);
    Point memory rH = pointMul(Point(H_X, H_Y), blindingFactor);
    Point memory C = pointAdd(vG, rH);
    return (C.x, C.y);
}

Properties:

• Perfectly hiding (reveals nothing about value)
• Computationally binding (cannot find different opening)
• Homomorphic (C1 + C2 commits to v1 + v2)

Gas: ~12,000 gas (vs 100,000+ in pure Solidity)

Live Demo: Try /pvm page → BN128 Pedersen Commitment

Why: When sr25519/ed25519/XCM precompiles deploy, features activate automatically.

Implementation: contracts/src/libraries/PvmVerifier.sol, contracts/src/interfaces/IPolkadotPrecompiles.sol

Detection Matrix:

Graceful Degradation: Functions return false when precompiles unavailable, no reverts.

contracts/src/
├── CryptoRegistry.sol          # Central precompile registry (Track 2 core)
├── StealthPayment.sol          # EIP-5564 stealth addresses
├── OmniShieldEscrow.sol        # Multi-party escrow
├── YieldRouter.sol             # Cross-chain yield
├── XcmRouter.sol               # XCM dispatcher
├── libraries/
│   ├── PvmBlake2.sol           # Blake2b integration (Phase 1)
│   ├── PvmVerifier.sol         # Sr25519/Ed25519/BN128 (Phase 2)
│   ├── BN128Stealth.sol        # Pedersen commitments (Phase 3)
│   └── SubstrateCompat.sol     # Substrate helpers
└── interfaces/
    ├── IPolkadotPrecompiles.sol # Precompile specs
    └── ...

Total Tests: 170+

Quick demo path for judges:

1. Homepage (/) — Track 2 banner and overview
2. PVM Registry (/pvm) — Live Blake2b hashing + Pedersen commitment demo
3. Stealth Payments (/stealth) — Private payment flow
4. Code walkthrough — Show precompile integration

• Demo video URL: <ADD_DEMO_VIDEO_LINK>

✅ Real Precompile Integration — ACTUAL precompile calls, not mocks ✅ Production-Ready — 170+ tests, error handling, gas optimization ✅ Substrate Compatible — Blake2b accounts, storage keys, XCM hashing ✅ Graceful Degradation — Auto-detect and adapt to precompile availability

This README is the canonical submission document and includes:

• Problem statement and track mapping
• Live deployment details
• Contract architecture and precompile integration
• Test coverage summary
• Judge demo path
• Local installation and verification steps
• Future roadmap and commitment

• Node.js 20+
• npm
• Foundry (forge, cast)

cd contracts
forge install
forge build
forge test -vv

cd frontend
npm install
npm run dev
# Open http://localhost:3000

cd backend
cp .env.example .env
# Fill .env with contract addresses and relayer key
npm install
npm run dev

• Polkadot.js wallet signature verification
• Gasless transactions for Substrate users
• Cross-ecosystem identity bridge

• Native DOT/KSM transfers from EVM
• Cross-parachain messaging
• Governance triggers from smart contracts

• Range proofs using BN128 pairing (0x08)
• zk-SNARKs for private transactions
• Confidential asset registry

• Polkadot Team: For PVM architecture and Frontier EVM
• Parity Technologies: For Substrate & Polkadot.js
• Moonbeam Team: For precompile design patterns
• EIP-5564 Authors: For stealth address specification

MIT License. See LICENSE.