RWA Tokenization — Real-World Assets on Dong Chain

Overview

Dong Chain provides a two-layer RWA tokenization architecture:

1. Layer 0 (Bitcoin/OmniCore): Immutable issuance registry — highest censorship resistance
2. Layer 1 (Dong Chain): Programmable token with DeFi capabilities

Supported Asset Classes

Asset Class	Example	Issuance Layer	Smart Contract Features
Real estate	Apartment buildings, office towers	OmniCore L0	Dividend distribution, fractional ownership
Treasury bonds	Government bonds	OmniCore L0	Interest payments, maturity redemption
Commodities	Gold, oil certificates	OmniCore L0	Price oracle integration
Private equity	Fund shares	OmniCore L0	Whitelist compliance, transfer restrictions
Gaming land	Virtual territory	Dong Chain L1	Play-to-earn mechanics, rental income
IP rights	Music royalties, patents	OmniCore L0	Streaming revenue distribution

End-to-End Asset Lifecycle

Phase 1: Issue on Bitcoin (Layer 0)

# Step 1: Verify OmniCore node is running
omnicore-cli getblockchaininfo

# Step 2: Issue RWA token
omnicore-cli omni_sendissuancefixed \
  "bc1qISSUER_ADDRESS" \    # Issuer's Bitcoin address
  1 \                        # Ecosystem: 1=mainnet
  2 \                        # Type: 2=divisible (like shares)
  0 \                        # PreviousID: 0 for new token
  "Real Estate" \            # Category
  "Commercial" \             # Subcategory
  "Hanoi Office Tower A" \   # Token name
  "https://issuer.io/hat-a" \# Information URL
  "Tokenized 30% ownership of 100 Nguyen Hue, Hanoi, Vietnam. Total value: $5M USD" \
  "15000000"                 # Supply: 15,000,000 shares (each = $0.33 face value)

# Response:
# {
#   "txid": "abc123...",  <- Permanently on Bitcoin blockchain
#   "propertyid": 42      <- Unique RWA identifier
# }

# Step 3: Verify issuance
omnicore-cli omni_getproperty 42

Phase 2: Bridge to Dong Chain (BitVM2)

# Transfer OmniCore asset to BitVM2 bridge address
omnicore-cli omni_send \
  "bc1qISSUER_ADDRESS" \
  "bc1qBITVM2_BRIDGE_ADDRESS" \   # Computed from BitVM2 setup ceremony
  42 \                             # Property ID
  "15000000"                       # Amount to bridge

# Wait for 6 Bitcoin block confirmations (~60 minutes)
# Oracle automatically detects and mints wrapped token on Dong Chain

Phase 3: Program on Dong Chain (RISC-V)

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.24;

import "@openzeppelin/contracts/token/ERC20/ERC20.sol";
import "@openzeppelin/contracts/access/Ownable.sol";

/// @title HanoiOfficeTowerA
/// @notice Wrapped RWA token for real estate ownership
///         Backed 1:1 by OmniCore property #42 on Bitcoin L0
contract HanoiOfficeTowerA is ERC20, Ownable {
    // ─── Compliance ───────────────────────────────────────────────────────────
    mapping(address => bool) public kycApproved;
    address public immutable BRIDGE_ORACLE;

    uint256 public dividendPerShare;
    mapping(address => uint256) public claimedDividend;

    event DividendDistributed(uint256 amount, uint256 perShare);
    event KYCApproved(address investor);
    event KYCRevoked(address investor);

    // ─── Constructor ──────────────────────────────────────────────────────────
    constructor(address oracle) ERC20("Hanoi Office Tower A", "HOTA") Ownable(msg.sender) {
        BRIDGE_ORACLE = oracle;
    }

    // ─── Minting (bridge oracle only) ─────────────────────────────────────────
    /// @notice Called by BitVM2 oracle when peg-in confirmed
    function mintBridged(address recipient, uint256 amount) external {
        require(msg.sender == BRIDGE_ORACLE, "Not oracle");
        require(kycApproved[recipient], "KYC required");
        _mint(recipient, amount);
    }

    // ─── KYC Compliance ───────────────────────────────────────────────────────
    function approveKYC(address investor) external onlyOwner {
        kycApproved[investor] = true;
        emit KYCApproved(investor);
    }

    function revokeKYC(address investor) external onlyOwner {
        kycApproved[investor] = false;
        emit KYCRevoked(investor);
    }

    // ─── Transfer with compliance check ───────────────────────────────────────
    function _update(address from, address to, uint256 value) internal override {
        if (to != address(0) && from != address(0)) {
            require(kycApproved[to], "Recipient not KYC approved");
        }
        super._update(from, to, value);
    }

    // ─── Dividend Distribution ────────────────────────────────────────────────
    /// @notice Distribute rental income to token holders (quarterly)
    function distributeDividend() external payable onlyOwner {
        require(totalSupply() > 0, "No supply");
        uint256 perShare = msg.value * 1e18 / totalSupply();
        dividendPerShare += perShare;
        emit DividendDistributed(msg.value, perShare);
    }

    /// @notice Claim accumulated dividend
    function claimDividend() external {
        uint256 owed = (dividendPerShare - claimedDividend[msg.sender])
                       * balanceOf(msg.sender) / 1e18;
        require(owed > 0, "Nothing to claim");
        claimedDividend[msg.sender] = dividendPerShare;
        payable(msg.sender).transfer(owed);
    }
}

Phase 4: DeFi Integration

Once on Dong Chain, RWA tokens can participate in DeFi:

// Example: Use tokenized real estate as loan collateral
// (Aave-like lending protocol on Dong Chain)

interface ILendingPool {
    function deposit(address asset, uint256 amount) external;
    function borrow(address asset, uint256 amount) external;
}

// User deposits HOTA (real estate token) as collateral
lendingPool.deposit(HOTA_ADDRESS, 1000 * 1e18);

// User borrows USDC against real estate collateral
lendingPool.borrow(USDC_ADDRESS, 500 * 1e18);

Compliance Framework

Transfer Restrictions

RWA tokens often require compliance rules:

// Transfer restriction types
enum RestrictionType {
    NONE,           // No restrictions (gaming assets, commodities)
    KYC_ONLY,       // Requires KYC verification
    ACCREDITED,     // Accredited investors only
    JURISDICTION,   // Geographic restrictions
    LOCKUP          // Time-based lockup period
}

On-Chain Audit Trail

Every transfer is permanently recorded:

Bitcoin L0: Original issuance → immutable forever
Dong Chain: All transfer events → queryable via JSON-RPC
ZK Proof: Batch summary → Bitcoin finality every 24h

Cross-Chain Yield Distribution

RWA income can flow across chains via Relay Depository:

[Real Estate Rental Income (USDC on Ethereum)]
        │
        ▼ Relay Depository cross-chain transfer
[USDC received on Dong Chain]
        │
        ▼ Smart contract dividend distribution
[Token holders receive pro-rata income]

Legal & Regulatory Considerations

Disclaimer: This documentation is for technical reference only. Consult legal counsel in your jurisdiction before tokenizing real-world assets.

Key areas to address:

• Securities regulations (SEC in US, SFC in HK, etc.)
• KYC/AML requirements
• Investor accreditation standards
• Cross-border transfer rules
• Token custody and recovery procedures

The smart contract layer provides technical enforcement; legal compliance is the issuer's responsibility.

Related Docs

• Layer 0 — Bitcoin & OmniCore
• BitVM2 Bridge
• Security Model