Dojang (Attestations)

This guide explains the Dojang attestation service based on EAS (Ethereum Attestation Service).

Attestation Creation

Attestations can only be created by official issuers (e.g., Upbit Korea). This SDK provides read-only access for verifying attestations.

See: Dojang Documentation

What is Dojang?

Dojang is GIWA Chain's attestation service that connects on-chain wallet addresses with off-chain information. It enables users to establish identity without exposing personally identifiable information (PII) directly.

Attestation Types

Type	Description
Verified Address	KYC-verified wallet address
Balance Root	Merkle tree summary of balances
Verified Balance	Balance attestation at specific time
Verified Code	On-chain verification of off-chain codes

useDojang Hook

import { useDojang } from 'giwa-react-native-wallet';

function DojangScreen() {
  const {
    getAttestation,       // Get attestation by UID
    isAttestationValid,   // Check if attestation is valid
    hasVerifiedAddress,   // Check if address has verified attestation
    getVerifiedBalance,   // Get verified balance data
    isLoading,
    isInitializing,
    error,
  } = useDojang();

  // ...
}

Get Attestation

const handleGetAttestation = async () => {
  const attestationUid = '0x...'; // Attestation UID

  try {
    const attestation = await getAttestation(attestationUid);

    if (attestation) {
      console.log('Attester:', attestation.attester);
      console.log('Recipient:', attestation.recipient);
      console.log('Type:', attestation.attestationType);
      console.log('Issued:', attestation.time);
      console.log('Revoked:', attestation.revoked);
    } else {
      console.log('Attestation not found');
    }
  } catch (error) {
    console.error('Lookup failed:', error.message);
  }
};

Verify Attestation

Check if an attestation is valid (exists and not revoked):

const handleVerify = async () => {
  const attestationUid = '0x...';

  const isValid = await isAttestationValid(attestationUid);

  if (isValid) {
    console.log('Attestation is valid');
  } else {
    console.log('Attestation is invalid or revoked');
  }
};

Get Verified Balance

For verified_balance type attestations:

const handleGetBalance = async () => {
  const attestationUid = '0x...';

  const result = await getVerifiedBalance(attestationUid);

  if (result) {
    console.log('Balance:', result.balance);
    console.log('Timestamp:', result.timestamp);
  }
};

Check Verified Address

Check if a wallet address has a verified attestation:

const handleCheckVerified = async () => {
  const address = '0x742d35Cc6634C0532925a3b844Bc9e7595f...';

  const isVerified = await hasVerifiedAddress(address);

  if (isVerified) {
    console.log('Address is verified');
  } else {
    console.log('Address is not verified');
  }
};

Complete Example

import { useState } from 'react';
import { View, Text, TextInput, Button, Alert } from 'react-native';
import { useDojang } from 'giwa-react-native-wallet';

export function DojangScreen() {
  const {
    getAttestation,
    isAttestationValid,
    hasVerifiedAddress,
    isLoading,
    isInitializing,
    error,
  } = useDojang();
  const [uid, setUid] = useState('');
  const [attestation, setAttestation] = useState(null);

  const handleLookup = async () => {
    if (!uid) return;

    const att = await getAttestation(uid);
    setAttestation(att);
  };

  const handleVerify = async () => {
    if (!uid) return;

    const isValid = await isAttestationValid(uid);
    Alert.alert(
      'Verification Result',
      isValid ? 'Valid attestation' : 'Invalid or revoked attestation'
    );
  };

  const getTypeName = (type: string) => {
    switch (type) {
      case 'verified_address':
        return 'Verified Address';
      case 'balance_root':
        return 'Balance Root';
      case 'verified_balance':
        return 'Verified Balance';
      case 'verified_code':
        return 'Verified Code';
      default:
        return type;
    }
  };

  if (isInitializing) {
    return <Text>Loading...</Text>;
  }

  return (
    <View style={{ padding: 20 }}>
      <Text style={{ fontSize: 20, marginBottom: 20 }}>Dojang Attestations</Text>

      {error && (
        <Text style={{ color: 'red', marginBottom: 10 }}>{error.message}</Text>
      )}

      <Text style={{ marginBottom: 5 }}>Attestation UID</Text>
      <TextInput
        placeholder="0x..."
        value={uid}
        onChangeText={setUid}
        style={{
          borderWidth: 1,
          borderColor: '#ccc',
          padding: 10,
          marginBottom: 10,
          fontFamily: 'monospace',
        }}
      />

      <View style={{ flexDirection: 'row', marginBottom: 20 }}>
        <Button title="Lookup" onPress={handleLookup} disabled={isLoading} />
        <View style={{ width: 10 }} />
        <Button title="Verify" onPress={handleVerify} disabled={isLoading} />
      </View>

      {attestation && (
        <View
          style={{
            backgroundColor: attestation.revoked ? '#ffebee' : '#e8f5e9',
            padding: 15,
            borderRadius: 8,
          }}
        >
          <Text style={{ fontWeight: 'bold', marginBottom: 10 }}>
            {getTypeName(attestation.attestationType)}
          </Text>

          <Text>Attester: {attestation.attester.slice(0, 20)}...</Text>
          <Text>Recipient: {attestation.recipient.slice(0, 20)}...</Text>
          <Text>
            Issued: {new Date(Number(attestation.time) * 1000).toLocaleString()}
          </Text>

          {attestation.revoked && (
            <Text style={{ color: 'red', marginTop: 10 }}>
              This attestation has been revoked
            </Text>
          )}
        </View>
      )}
    </View>
  );
}

Use Cases

Check if Address is Verified

const checkVerifiedAddress = async (address: string) => {
  // Simple check using hasVerifiedAddress
  const isVerified = await hasVerifiedAddress(address);
  return isVerified;
};

// Or with detailed information
const checkVerifiedAddressDetailed = async (attestationUid: string) => {
  const attestation = await getAttestation(attestationUid);

  if (!attestation) {
    return { verified: false, reason: 'Attestation not found' };
  }

  if (attestation.revoked) {
    return { verified: false, reason: 'Attestation revoked' };
  }

  if (attestation.attestationType !== 'verified_address') {
    return { verified: false, reason: 'Wrong attestation type' };
  }

  return { verified: true, address: attestation.recipient };
};

Verify Before Transaction

const sendToVerifiedAddress = async (attestationUid: string, amount: string) => {
  // Verify attestation first
  const isValid = await isAttestationValid(attestationUid);
  if (!isValid) {
    throw new Error('Invalid or revoked attestation');
  }

  // Get recipient address
  const attestation = await getAttestation(attestationUid);
  if (!attestation) {
    throw new Error('Attestation not found');
  }

  // Send transaction
  return sendTransaction({
    to: attestation.recipient,
    value: amount,
  });
};

Next Steps

• Security - Security best practices
• GIWA ID - Naming service