Confidential Assets: Private Tokens by Design

// Traditional approach - everything is public
contract Token {
    mapping(address => uint256) public balances; // ❌ Public balances
 
    function transfer(address to, uint256 amount) public {
        require(balances[msg.sender] >= amount); // ❌ Public amounts
        balances[msg.sender] -= amount;          // ❌ Public operations
        balances[to] += amount;                  // ❌ All visible on-chain
    }
}

// TOS native asset - everything is private by default
struct ConfidentialAsset {
    asset_id: Hash,
    encrypted_supply: ElGamalCiphertext,     // ✅ Hidden total supply
    encrypted_balances: Map<Address, ElGamalCiphertext>, // ✅ Hidden balances
    privacy_settings: PrivacyConfiguration   // ✅ Configurable privacy
}
 
// Transfer operation
fn transfer(from: Address, to: Address, encrypted_amount: ElGamalCiphertext) {
    // ✅ Amount remains encrypted throughout
    // ✅ Zero-knowledge proof validates without revealing
    // ✅ Homomorphic operations preserve privacy
    // ✅ Native blockchain execution (no smart contract)
}

Privacy Features Applied to Every Asset:
├── Homomorphic Encryption: Encrypted balances and amounts
├── Zero-Knowledge Proofs: Transaction validity without revelation
├── Range Proofs: Prevent negative amounts and overflow
├── Balance Proofs: Ensure sufficient funds without disclosure
└── Bulletproof Optimization: Fast verification and small proofs

Single Transaction Example:
- Send 100 USDT (encrypted) → Alice
- Send 50 TOS (encrypted) → Bob
- Send 25 GOLD tokens (encrypted) → Charlie
All amounts remain completely private

// Atomic multi-asset transfer
Transaction {
    transfers: vec![
        Transfer { asset: USDT, from: user, to: alice, amount: Encrypt(100) },
        Transfer { asset: TOS, from: user, to: bob, amount: Encrypt(50) },
        Transfer { asset: GOLD, from: user, to: charlie, amount: Encrypt(25) }
    ],
    // Single zero-knowledge proof validates all transfers
    proof: MultiAssetZKProof::generate(transfers)
}

// Create a new confidential asset
const assetConfig = {
    name: "Privacy Coin",
    symbol: "PRIV",
    decimals: 8,
    totalSupply: 1000000, // Will be encrypted
    privacyLevel: "Maximum",
    governance: {
        canMint: true,
        canBurn: true,
        canFreeze: false
    }
}
 
const asset = await tosNetwork.createConfidentialAsset(assetConfig)

// Private asset distribution
const distribution = await asset.distributeTokens({
    recipients: [
        { address: "tos1abc...", amount: 10000 }, // Amount encrypted automatically
        { address: "tos1def...", amount: 15000 }, // Recipient only knows their amount
        { address: "tos1ghi...", amount: 25000 }  // Network verifies without seeing amounts
    ],
    proof: await generateDistributionProof(recipients)
})

// Create a private USDT equivalent
const privateUSDT = await tosNetwork.createConfidentialAsset({
    name: "Private USD Tether",
    symbol: "pUSDT",
    decimals: 6,
    privacyLevel: "Maximum",
    oracle: "chainlink-usd",
    compliance: {
        kycRequired: false,
        geographicRestrictions: [],
        reportingLevel: "privacy-preserving"
    }
})

// Company equity tokens with complete privacy
const equityToken = await tosNetwork.createConfidentialAsset({
    name: "TechCorp Equity",
    symbol: "TECH",
    decimals: 0, // Whole shares only
    privacyLevel: "Maximum",
    governance: {
        votingRights: true,
        dividendRights: true,
        transferRestrictions: "accredited-investors-only"
    }
})

// Gaming currency with privacy
const gameToken = await tosNetwork.createConfidentialAsset({
    name: "Game Gold",
    symbol: "GGOLD",
    decimals: 2,
    privacyLevel: "High",
    gaming: {
        inGameUtility: true,
        crossGameCompatible: true,
        antiBot: true
    }
})

// Privacy-preserving CBDC
const digitalEuro = await tosNetwork.createConfidentialAsset({
    name: "Digital Euro",
    symbol: "DEUR",
    decimals: 2,
    privacyLevel: "Selective",
    governance: {
        centralBankControl: true,
        programmableMoney: true,
        complianceIntegration: true
    },
    privacy: {
        citizenPrivacy: "maximum",
        governmentVisibility: "compliance-only",
        auditTrail: "encrypted"
    }
})

pub struct ConfidentialAsset {
    // Asset identification
    pub asset_id: Hash,
    pub name: String,
    pub symbol: String,
    pub decimals: u8,
 
    // Privacy-preserving supply management
    pub encrypted_total_supply: ElGamalCiphertext,
    pub supply_proof: SupplyZKProof,
 
    // Account balances (all encrypted)
    pub balances: BTreeMap<PublicKey, ElGamalCiphertext>,
 
    // Governance and permissions
    pub creator: PublicKey,
    pub governance_rules: GovernanceConfiguration,
    pub privacy_settings: PrivacyConfiguration,
 
    // Metadata (can be encrypted based on privacy level)
    pub metadata: AssetMetadata,
}

// Multi-asset transaction processing
pub fn process_confidential_transfer(
    transaction: MultiAssetTransaction
) -> Result<(), TransactionError> {
    // Verify zero-knowledge proofs for all assets
    for transfer in &transaction.transfers {
        verify_asset_transfer_proof(
            &transfer.asset_id,
            &transfer.encrypted_amount,
            &transfer.balance_proof,
            &transfer.range_proof
        )?;
    }
 
    // Update all balances atomically
    for transfer in transaction.transfers {
        update_encrypted_balance(
            &transfer.asset_id,
            &transfer.from,
            &transfer.to,
            &transfer.encrypted_amount
        )?;
    }
 
    Ok(())
}

// Atomic cross-asset swaps
pub struct ConfidentialSwap {
    pub asset_a: Hash,
    pub asset_b: Hash,
    pub encrypted_amount_a: ElGamalCiphertext,
    pub encrypted_amount_b: ElGamalCiphertext,
    pub swap_proof: CrossAssetZKProof, // Proves fair exchange without revealing amounts
}

// Generate compliance proof without revealing amounts
const complianceProof = await asset.generateComplianceProof({
    transactionId: "tx123",
    regulatoryFramework: "EU-MiCA",
    disclosureLevel: "transaction-validity-only",
    authorizedParty: "financial-intelligence-unit"
})
 
// Proof demonstrates:
// ✅ Transaction follows all rules
// ✅ No money laundering patterns
// ✅ Proper KYC/AML compliance
// ❌ Does not reveal actual amounts
// ❌ Does not expose trading patterns

// Encrypted audit trail for regulatory review
const auditTrail = await asset.generateAuditTrail({
    timeRange: { start: "2024-01-01", end: "2024-12-31" },
    scope: "all-transactions",
    encryption: "regulator-public-key",
    proofLevel: "zero-knowledge"
})

Storage per Asset:
├── Asset Definition: ~1KB
├── Per-Account Balance: ~64 bytes (encrypted)
├── Transaction History: ~1KB per transaction
└── Total Overhead: Minimal compared to smart contracts

const TOS = require('@tos-network/sdk')
 
// Initialize TOS Network connection
const tos = new TOS.Network('mainnet')
 
// Create asset with full privacy
const myAsset = await tos.assets.create({
    name: "My Private Token",
    symbol: "MPT",
    decimals: 8,
    initialSupply: 1000000,
    privacyLevel: "maximum",
    distributionStrategy: "private-sale"
})
 
console.log(`Asset created: ${myAsset.id}`)

// Get encrypted balance (only visible to owner)
const encryptedBalance = await myAsset.getBalance(userAddress)
const actualBalance = await tos.crypto.decrypt(encryptedBalance, privateKey)
 
// Send private transaction
const transaction = await myAsset.transfer({
    from: senderAddress,
    to: recipientAddress,
    amount: 100, // Will be encrypted automatically
    privacy: "maximum"
})
 
// Verify transaction without seeing amounts
const isValid = await tos.verify.transaction(transaction)

// Atomic multi-asset transfer
const multiTransfer = await tos.assets.atomicTransfer([
    { asset: "TOS", to: alice, amount: 50 },
    { asset: "USDT", to: bob, amount: 100 },
    { asset: "GOLD", to: charlie, amount: 25 }
])
 
// All transfers execute together or none execute
await multiTransfer.execute()