Vortex

Private transactions on Sui using zero-knowledge proofs.

Vortex is a privacy protocol that breaks the on-chain link between deposit and withdrawal addresses. Users deposit SUI into a shared pool, then withdraw to any address without revealing which deposit they own.

How it works

1. Deposit - Send SUI to the pool. You receive an encrypted note (UTXO) that proves ownership.
2. Transfer - Encrypt a note with someone's public key. Only they can decrypt and spend it.
3. Withdraw - Generate a ZK proof that you own a valid note, without revealing which one.

The protocol uses a 2-input/2-output UTXO model. Each transaction consumes up to 2 existing notes and creates 2 new ones (one for the recipient, one for change).

Project structure

vortex-v2/
├── contracts/     # Move smart contracts (Sui)
├── circuit/       # Rust zkSNARK circuit (Groth16)
├── indexer/       # Rust indexer for tracking commitments
└── api/           # TypeScript REST API

Contracts

The Move contracts handle:

• Proof verification (native Groth16 on Sui)
• Merkle tree for commitment storage
• Nullifier tracking to prevent double-spends
• Encryption key registry for receiving transfers

Circuit

The Rust circuit generates Groth16 proofs that verify:

• Input notes exist in the Merkle tree
• Nullifiers are correctly computed
• Output commitments are well-formed
• Amounts balance (inputs = outputs + public delta)

Compiles to WASM for browser-based proof generation.

Indexer

Rust service that:

• Indexes commitment events from Sui
• Maintains Merkle tree state
• Provides API for building proofs

API

REST API for:

• Account management
• Transaction building
• Merkle tree queries

Development

Prerequisites

• Rust 1.70+
• Sui CLI 1.59+
• Bun
• wasm-pack (for browser builds)

Building

# Contracts
cd contracts && sui move build

# Circuit
cd circuit && cargo build --release

# Indexer
cd indexer && cargo build --release

# API
cd api && bun install && bun run build

Testing

# Contracts
cd contracts && sui move test

# Circuit
cd circuit && cargo test

# Indexer
cd indexer && cargo test

# API
cd api && bun test

SDK

The TypeScript SDK is published separately at @interest-protocol/vortex-sdk.

npm install @interest-protocol/vortex-sdk

Basic usage:

import { VortexKeypair, deposit, withdraw } from '@interest-protocol/vortex-sdk';

// Create keypair from Sui wallet
const keypair = await VortexKeypair.fromSuiWallet(address, signFn);

// Deposit
const tx = await deposit({ amount: 1_000_000_000n, ... });

// Withdraw
const tx = await withdraw({ amount: 500_000_000n, recipient: '0x...', ... });

Deployed contracts (Testnet)

Package:   0xcf81b96e392f82b776ee980108357426b726c4043c838822545a307e12c5ded6
Registry:  0xf2c11c297e0581e0279714f6ba47e26d03d9a70756036fab5882ebc0f1d2b3b1

Privacy considerations

Hidden: Which deposit funded a withdrawal. Transaction amounts. Sender/recipient relationship.

Public: Total pool balance. Number of commitments. When transactions occurred. Nullifiers (but they can't be linked to commitments).

Privacy depends on the anonymity set. More users = better privacy. Avoid depositing and withdrawing the same amount in quick succession.

Security

This is experimental software. The circuit uses Groth16 with a trusted setup. Key management is critical - losing your Vortex private key means losing access to your funds.

License

MIT