> ## Documentation Index
> Fetch the complete documentation index at: https://docs.artstarex.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Technology and Security

> ArtStar tokenizes RWA assets based on the ERC-20 standard and uses on-chain signature verification plus compliance contracts to form a full compliance management framework.

Built on mainstream public blockchain infrastructure, ArtStar tokenizes physical artworks under the ERC-20 standard and establishes an on-chain compliance management contract framework. This architecture preserves transaction transparency while delivering institutional-grade asset security and compliance control.

## Tokenization Architecture

### ERC-20 Tokenization Standard

ArtStar uses the [ERC-20](https://ethereum.org/en/developers/docs/standards/tokens/erc-20/) standard as the base protocol for asset tokenization.

| Parameter        | Configuration Value              | Description                                                   |
| ---------------- | -------------------------------- | ------------------------------------------------------------- |
| **Decimals**     | 18                               | High precision to support flexible fractional ownership       |
| **Symbol**       | ARTS / asset-specific symbol     | Easy for market recognition and exchange listings             |
| **Total Supply** | Anchored to physical asset value | Fixed in aggregate through the compliance management contract |

### Tokenization Workflow

```text theme={null}
Physical asset valuation -> Legal structuring -> Smart contract deployment -> KYC/AML verification -> Token issuance
```

1. **Asset Preparation**: Conduct professional valuation of the physical artwork and design the legal structure, such as an SPV or direct tokenization.
2. **Custody Arrangement**: Appoint a qualified custodian to safeguard the physical asset and ensure the asset is securely ring-fenced.
3. **Contract Deployment**: Deploy token contracts that comply with ArtStar standards on BNB Chain (BSC).
4. **Identity Verification**: Investors complete KYC/AML procedures and their wallet addresses are added to the whitelist.
5. **Token Distribution**: After compliance checks pass, tokens are securely distributed to investor wallets.

## Compliance Contract Framework

### ComplianceManage Contract Architecture

ArtStar has built a complete on-chain compliance contract framework that delivers institutional-grade compliance control through signature-based authorization.

### On-Chain Signature Verification

The compliance management contract uses ECDSA signature verification to ensure that only properly authorized actions can be executed:

```solidity theme={null}
// Core signature verification logic
function _verifySignature(
        address user,
        bytes memory signature,
        uint8 operation,
        uint256 expireTime
    ) internal virtual returns (bool) {
        if (block.timestamp > expireTime) revert SignatureExpired();

        bytes32 messageHash = keccak256(
            abi.encodePacked(block.chainid, address(this), user, txNonce[user], operation, expireTime)
        );

        bytes32 ethSignedHash = MessageHashUtils.toEthSignedMessageHash(messageHash);

        address recovered = ECDSA.recover(ethSignedHash, signature);

        if (recovered != owner() && subAdmins[recovered].permissionLevel != PERMISSION_SIGNATURE_MANAGER) return false;

        txNonce[user]++;

        return true;
    }
```

### Whitelist Management

| Function               | Description                                                 | Permission Requirement      |
| ---------------------- | ----------------------------------------------------------- | --------------------------- |
| **Address Onboarding** | Add investor addresses that passed KYC to the whitelist     | Compliance administrator    |
| **Batch Updates**      | Support batch addition or removal of blacklisted addresses  | Compliance admin + multisig |
| **Status Query**       | Query an address's compliance status in real time           | Public interface            |
| **Automated Checks**   | Automatically validate both counterparties during transfers | Inline contract logic       |

### Compliance Parameters

| Parameter                 | Configuration Item    | Description                                              |
| ------------------------- | --------------------- | -------------------------------------------------------- |
| **Investment Limits**     | Min/Max Investment    | USD limits for a single investment                       |
| **Raise Limits**          | Min/Max Raise         | Target fundraising range for an issuance round           |
| **Lock-Up Period**        | Lock Duration         | Vesting or holding period after token delivery           |
| **Transfer Restrictions** | Transfer Restrictions | Transfers involving blacklisted addresses are prohibited |

## Blockchain Infrastructure

### BNB Chain Multi-Layer Architecture

ArtStar selects BNB Chain as its primary deployment network and benefits from its mature infrastructure:

| Chain                     | Role          | Key Characteristics                                            |
| ------------------------- | ------------- | -------------------------------------------------------------- |
| **BSC (BNB Smart Chain)** | Main network  | Scalable, low cost, secure, and production-ready               |
| **opBNB**                 | Scaling layer | Higher TPS and lower gas, suitable for high-frequency activity |

### Chain Selection Considerations

| Consideration         | BSC Advantage                | L2 Option                                      |
| --------------------- | ---------------------------- | ---------------------------------------------- |
| **Gas Fees**          | Very low (about \$0.05/tx)   | Can be reduced by another 10x-100x             |
| **Transaction Speed** | \~3-second block time        | Near-instant confirmation                      |
| **Ecosystem**         | Mature and tooling-rich      | Rapidly evolving                               |
| **Use Cases**         | Standard trading and staking | High-frequency trading and small-ticket assets |

## Security Architecture

### Layered Security Controls

```text theme={null}
┌────────────────────────────────────────────────────────────┐
│                     Security Architecture                  │
├────────────────────────────────────────────────────────────┤
│  Layer 1: Smart Contract Security                         │
│    - Professional security audits by independent firms    │
│    - Formal verification                                  │
│    - Bug bounty program                                   │
│                                                            │
│  Layer 2: Access Control                                  │
│    - Multi-signature wallets for sensitive operations     │
│    - Timelock protection for critical actions             │
│    - Role-based access control                            │
│                                                            │
│  Layer 3: Compliance Verification                         │
│    - KYC/AML identity verification                        │
│    - On-chain signature verification                      │
│    - Whitelist controls                                   │
│                                                            │
│  Layer 4: Asset Custody                                   │
│    - Physical assets: qualified custodians / trustees     │
│    - Digital assets: MPC + HSM cold storage               │
└────────────────────────────────────────────────────────────┘
```

### Smart Contract Audits

ArtStar smart contracts must go through the following security assurance process:

1. **Internal Code Review**: Multiple rounds of review performed by the development team.
2. **Third-Party Security Audit**: Independent blockchain security firms, such as Trail of Bits, CertiK, or OpenZeppelin, review the contracts.
3. **Formal Verification**: Critical logic is mathematically validated where appropriate.
4. **Testnet Validation**: Contracts are thoroughly exercised on test networks before mainnet deployment.
5. **Bug Bounty Program**: A continuous bug bounty program remains available after launch.

### Multisignature Governance

| Operation Type           | Signature Requirement            | Description                                             |
| ------------------------ | -------------------------------- | ------------------------------------------------------- |
| **Parameter Changes**    | 2/3 multisig                     | Update limits, lock-up duration, and similar parameters |
| **Whitelist Management** | Single admin signature + logging | Day-to-day operational action                           |
| **Asset Migration**      | 3/5 multisig                     | High-risk action requiring multiple approvals           |
| **Contract Upgrade**     | Timelock + multisig              | Includes a 48-hour delay window                         |

## Asset Custody Framework

### Physical Asset Custody

| Custody Element             | Description                                                      |
| --------------------------- | ---------------------------------------------------------------- |
| **Custodian Qualification** | Licensed professional custody institution                        |
| **Physical Security**       | Professional vaults, fire and water protection, and surveillance |
| **Insurance Coverage**      | Adequate property insurance coverage                             |
| **Periodic Audit**          | Independent verification of the physical asset's existence       |

### Digital Asset Custody

| Custody Method                     | Technical Implementation                             | Applicable Scenario            |
| ---------------------------------- | ---------------------------------------------------- | ------------------------------ |
| **MPC Wallet**                     | Private key sharding through multi-party computation | Institutional asset management |
| **Hardware Security Module (HSM)** | Dedicated hardware security chip                     | High-security storage          |
| **Multisig Wallet**                | Joint control by multiple parties                    | Large-value asset operations   |

## Compliance and Regulatory Framework

### International Compliance Standards

ArtStar aligns with the following international compliance standards:

| Compliance Area           | Standard / Regulation                  | Implementation Approach                                |
| ------------------------- | -------------------------------------- | ------------------------------------------------------ |
| **KYC**                   | FATF Recommendations                   | Identity verification + address whitelisting           |
| **AML**                   | Financial Action Task Force            | Transaction monitoring + suspicious activity reporting |
| **Securities Compliance** | Hong Kong SFO / relevant jurisdictions | ERC-3643-compatible design                             |
| **Data Protection**       | GDPR / PDPO                            | Minimal on-chain data + encrypted storage              |

### Independent Regulatory Review

> The ArtStar community will appoint internationally recognized independent professionals to conduct periodic independent regulatory reviews of physical assets. The review results will be disclosed to the public in a timely manner.

* **Review Frequency**: Quarterly or annual independent audits
* **Review Scope**: Physical asset existence, integrity, and custody compliance
* **Disclosure**: Transparent and public review reports

## Evolution of Compliance Token Standards

The ArtStar tokenization architecture is compatible with the following token standard evolution path:

| Standard     | Type               | Applicable Scenario                           | Compliance Capability                                  |
| ------------ | ------------------ | --------------------------------------------- | ------------------------------------------------------ |
| **ERC-20**   | Fungible token     | Current model for fractionalized art          | Basic compliance through whitelist controls            |
| **ERC-3643** | Permissioned token | Scenarios with higher compliance requirements | Native KYC/AML and investor eligibility controls       |
| **ERC-1400** | Security token     | Institutional-grade security tokenization     | Partitioned transfers and attached legal documentation |

> **Evolution Strategy**: ArtStar adopts a modular design that can progressively upgrade token standards in response to regulatory requirements, enabling a smooth transition from ERC-20 to ERC-3643 or ERC-1400.

## Technology Stack Overview

| Technical Component   | Technology Choice             | Description                                             |
| --------------------- | ----------------------------- | ------------------------------------------------------- |
| **Smart Contracts**   | Solidity + Hardhat            | Mainstream general-purpose contract stack               |
| **Frontend**          | Vite + React + TypeScript     | Modern Web3 application development                     |
| **Web3 Library**      | wagmi + viem                  | Consistent with ethers.js v6 best practices             |
| **Testing Framework** | Hardhat + Vitest              | Full-stack testing for contracts and components         |
| **Chain ID**          | BSC Mainnet: 56 / Testnet: 97 | Configured for the BSC network                          |
| **Identity**          | Supabase Auth / Privy         | Web3 identity with a familiar Web2-like user experience |

***

## References

* [BNB Chain RWA Tokenization Guide](https://docs.bnbchain.org/showcase/tokenization/rwa-tokenization/)
* [RWA Tokenization: Standards and Costs](https://www.rwa.io/post/ethereum-rwa-tokenization-standards-and-costs)
* [ERC-20 Standard](https://ethereum.org/en/developers/docs/standards/tokens/erc-20/)
* [ERC-3643](https://www.erc3643.org/)
* [OpenZeppelin Contracts](https://www.openzeppelin.com/contracts/)