XUNA Whitepaper

// Example of wallet verification using ECDSA signatures
async function verifyWalletOwnership(address, message, signature) {
  // Recover the public key from the signature
  const msgHash = ethers.utils.hashMessage(message);
  const msgHashBytes = ethers.utils.arrayify(msgHash);
  const recoveredPubKey = ethers.utils.recoverPublicKey(msgHashBytes, signature);
  const recoveredAddress = ethers.utils.computeAddress(recoveredPubKey);
  
  // Verify the recovered address matches the claimed address
  return recoveredAddress.toLowerCase() === address.toLowerCase();
}

I am the owner of this wallet. Requesting Xuna card at [timestamp]. Nonce: abc123

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.17;

contract XunaVerification {
    // Verify a signature is valid for a given address and message
    function verifySignature(
        address _signer,
        string memory _message,
        bytes memory _signature
    ) public pure returns (bool) {
        bytes32 messageHash = keccak256(abi.encodePacked(_message));
        bytes32 ethSignedMessageHash = keccak256(
            abi.encodePacked("\x19Ethereum Signed Message:\n32", messageHash)
        );
        
        (bytes32 r, bytes32 s, uint8 v) = splitSignature(_signature);
        
        return ecrecover(ethSignedMessageHash, v, r, s) == _signer;
    }
    
    // Split signature into r, s, v components
    function splitSignature(bytes memory sig)
        internal
        pure
        returns (bytes32 r, bytes32 s, uint8 v)
    {
        require(sig.length == 65, "Invalid signature length");
        
        assembly {
            r := mload(add(sig, 32))
            s := mload(add(sig, 64))
            v := byte(0, mload(add(sig, 96)))
        }
        
        if (v < 27) {
            v += 27;
        }
        
        return (r, s, v);
    }
}

// Request card issuance
async function requestCardIssuance(walletAddress, signedProof, cardTier) {
  // Create pseudonymous session with card issuer
  const session = await createPseudonymousSession();
  
  // Submit only the necessary verification data
  const response = await session.post('/api/issue-card', {
    wallet_proof: {
      address: walletAddress,
      signature: signedProof
    },
    card_tier: cardTier,
    // No personal information transmitted
  });
  
  // Return deposit address and card details
  return {
    depositAddress: response.deposit_address,
    cardDetails: {
      lastFour: response.card_last_four,
      expiryDate: response.expiry,
      virtual: response.is_virtual,
      cardImageUrl: response.card_image
    }
  };
}

// Monitor deposit address for incoming transactions
async function monitorDeposits(depositAddress, targetAmount) {
  return new Promise((resolve) => {
    const checkInterval = setInterval(async () => {
      // Check for new transactions to the deposit address
      const transactions = await getAddressTransactions(depositAddress);
      
      // Calculate total confirmed amount
      const confirmedAmount = transactions
        .filter(tx => tx.confirmations >= 6)
        .reduce((sum, tx) => sum + tx.amount, 0);
      
      if (confirmedAmount >= targetAmount) {
        clearInterval(checkInterval);
        
        // Trigger conversion process
        const conversionResult = await convertCryptoToFiat(
          depositAddress,
          confirmedAmount,
          'USD' // Target currency
        );
        
        // Update card balance
        await updateCardBalance(cardId, conversionResult.fiatAmount);
        
        resolve({
          cryptoAmount: confirmedAmount,
          fiatAmount: conversionResult.fiatAmount,
          conversionRate: conversionResult.rate,
          timestamp: new Date()
        });
      }
    }, 30000); // Check every 30 seconds
  });
}

// Security best practices for XUNA implementation
class XunaSecurityModel {
  constructor() {
    // Initialize with zero knowledge of user
    this.userMetadata = null;
    this.ipLogging = false;
    this.fingerprintTracking = false;
    
    // Setup secure communication channels
    this.setupEncryptedChannels();
  }
  
  setupEncryptedChannels() {
    // Use end-to-end encryption for all API communication
    this.apiEncryption = {
      algorithm: 'AES-256-GCM',
      keyRotationInterval: '24h',
      forwardSecrecy: true
    };
  }
  
  // Data minimization approach
  processUserRequest(walletAddress, signature) {
    // Only store cryptographic proof, nothing else
    return {
      walletVerified: this.verifySignature(walletAddress, signature),
      sessionId: this.generateAnonymousSession(),
      // No user data stored or logged
    };
  }
  
  generateAnonymousSession() {
    // Create session with no linkability to real identity
    return crypto.randomBytes(32).toString('hex');
  }
  
  // Implement secure data deletion
  cleanupAfterTransaction() {
    // Purge all temporary data after transaction completes
    this.temporaryData = null;
    // Zero out memory where sensitive data was stored
    this.secureErase();
  }
}

// Privacy-preserving implementation
class XunaPrivacyModel {
  constructor() {
    // Configure privacy settings
    this.privacySettings = {
      ipAddressStorage: 'none', // Don't store IP addresses
      deviceFingerprinting: false, // No device fingerprinting
      cookieUsage: 'minimal', // Only essential cookies
      dataRetention: {
        transactionHashes: '30d', // Keep only for 30 days
        walletAddresses: 'session-only', // Don't persist after session
        signatures: 'verification-only' // Only used during verification
      }
    };
  }
  
  // Implement privacy-preserving analytics
  collectAnonymousMetrics(action) {
    return {
      timestamp: this.roundToHour(new Date()), // Reduce timestamp precision
      actionType: this.generalizeAction(action), // Generalize action type
      // No user identifiers collected
    };
  }
  
  // Reduce timestamp precision to protect privacy
  roundToHour(date) {
    const rounded = new Date(date);
    rounded.setMinutes(0, 0, 0);
    return rounded;
  }
  
  // Generalize action types to protect privacy
  generalizeAction(action) {
    const actionMap = {
      'view_card_details': 'card_action',
      'check_balance': 'card_action',
      'fund_card': 'funding_action',
      // Map specific actions to general categories
    };
    
    return actionMap[action] || 'general_action';
  }
  
  // Implement secure data deletion
  implementForgetfulness() {
    // Automatically delete data after its purpose is fulfilled
    setInterval(() => {
      this.purgeExpiredData();
    }, 86400000); // Daily cleanup
  }
}

version: '3.8'

services:
  # API Gateway
  api-gateway:
    image: xuna/api-gateway:latest
    ports:
      - "443:443"
    environment:
      - NODE_ENV=production
    depends_on:
      - wallet-verification
      - card-issuance
      - crypto-conversion
    networks:
      - xuna-network
    deploy:
      replicas: 3
      update_config:
        parallelism: 1
        delay: 10s
      restart_policy:
        condition: on-failure

  # Wallet Verification Service
  wallet-verification:
    image: xuna/wallet-verification:latest
    environment:
      - NODE_ENV=production
    networks:
      - xuna-network
    deploy:
      replicas: 5
      resources:
        limits:
          cpus: '0.5'
          memory: 1G

  # Card Issuance Service
  card-issuance:
    image: xuna/card-issuance:latest
    environment:
      - NODE_ENV=production
      - ISSUER_API_KEY=${ISSUER_API_KEY}
    networks:
      - xuna-network
    secrets:
      - issuer_credentials
    deploy:
      replicas: 3

  # Crypto Conversion Service
  crypto-conversion:
    image: xuna/crypto-conversion:latest
    environment:
      - NODE_ENV=production
    networks:
      - xuna-network
    deploy:
      replicas: 3

  # Blockchain Listeners
  blockchain-listeners:
    image: xuna/blockchain-listeners:latest
    environment:
      - NODE_ENV=production
      - ETHEREUM_RPC=${ETHEREUM_RPC}
      - TON_API_KEY=${TON_API_KEY}
      - MONERO_NODE=${MONERO_NODE}
    networks:
      - xuna-network
    deploy:
      replicas: 5

networks:
  xuna-network:
    driver: overlay
    attachable: true

secrets:
  issuer_credentials:
    external: true