ZK TLSNotary P2P Order Smart Contract

Overview

This smart contract implements a peer-to-peer (P2P) order system for cryptocurrency trading, leveraging Zero-Knowledge TLS Notary proofs for secure and private transactions. The contract supports partial order filling, allowing for flexible trading options.

Features

• Create sell orders for cryptocurrencies
• Support for partial order filling
• ZK TLS Notary proof verification for secure transactions
• Cancel orders (including partially filled orders)
• Retrieve user orders

Contract Structure

The main components of the contract are:

1. Order<CoinType>: Struct representing an order
2. P2POrderbook<CoinType>: Struct managing the orderbook
3. Key functions for order management and execution

Key Functions

initialize<CoinType>(account: &signer)

Initializes the P2P orderbook for a specific coin type.

create_order<CoinType>(...)

Creates a new sell order with the following parameters:

• fiat_currency: The fiat currency for payment
• total_crypto_amount: Total amount of cryptocurrency to sell
• fiat_price_per_crypto: Price per unit of cryptocurrency in fiat
• payment_method: Accepted payment method
• min_crypto_amount: Minimum amount that can be purchased in a single transaction

cancel_order<CoinType>(account: &signer, order_id: u64)

Cancels an open or partially filled order.

fill_order<CoinType>(account: &signer, order_id: u64, crypto_amount: u64, zk_proof: vector<u8>)

Fills an order (partially or fully) with ZK proof verification.

get_user_orders<CoinType>(user: address): vector<u64>

Retrieves all order IDs associated with a user.

Order Statuses

• ORDER_STATUS_OPEN: Newly created order
• ORDER_STATUS_PARTIALLY_FILLED: Order that has been partially filled
• ORDER_STATUS_FILLED: Completely filled order
• ORDER_STATUS_CANCELLED: Cancelled order

Usage

1. Initialize the orderbook for a specific coin type.
2. Sellers create orders specifying the total amount, price, and minimum fill amount.
3. Buyers fill orders by providing the amount they want to purchase and a ZK proof of payment.
4. The contract verifies the ZK proof and updates the order status accordingly.
5. Sellers can cancel unfilled or partially filled orders at any time.

ZK Proof Verification

The verify_zk_proof<CoinType> function is a placeholder that needs to be implemented with the specific ZK TLS Notary proof verification logic. This function should verify:

1. The buyer has made the fiat payment
2. The proof demonstrates knowledge of the TLS session key
3. The payment details match the order and the crypto amount being purchased

Security Considerations

• Ensure proper implementation of the ZK proof verification logic.
• Implement secure fund locking and transfer mechanisms (not included in this contract).
• Consider adding time limits or expirations for orders.
• Implement proper access controls and ensure only authorized actions are permitted.

Testing

Use the initialize_for_testing<CoinType> function to set up the contract in a test environment.

Future Improvements

• Implement a dispute resolution mechanism.
• Add support for buy orders in addition to sell orders.
• Integrate with a price oracle for real-time price updates.
• Implement an order matching engine for automatic order filling.

License