# WIA-FIN-011 KYC/AML Standard
## Phase 3: Protocol Specification v1.0.0

**Status:** ✅ Complete  
**Last Updated:** 2025-12-25  
**Maintainer:** WIA Standards Committee

---

## 1. Overview

This specification defines the communication protocols, data exchange mechanisms, and integration patterns for KYC/AML systems.

---

## 2. Communication Protocols

### 2.1 HTTP/HTTPS Protocol

**Requirements:**
- TLS 1.2 or higher mandatory
- HTTP/2 supported for improved performance
- Certificate pinning recommended
- Perfect Forward Secrecy (PFS) required

**Headers:**
```
Content-Type: application/json
Accept: application/json
Authorization: Bearer {token}
X-Request-ID: uuid
X-Correlation-ID: uuid
User-Agent: KYC-Client/1.0
```

### 2.2 WebSocket Protocol

For real-time monitoring and alerts:

```javascript
wss://api.kyc-aml.example.com/v1/stream
Connection: Upgrade
Upgrade: websocket
Sec-WebSocket-Version: 13
Sec-WebSocket-Key: {key}

// Subscribe to events
{
  "action": "subscribe",
  "channels": ["alerts", "transactions"]
}

// Receive events
{
  "channel": "alerts",
  "event": "alert.generated",
  "data": { ... }
}
```

### 2.3 Message Queue Integration

**Supported Protocols:**
- AMQP (RabbitMQ, Azure Service Bus)
- Kafka Protocol
- MQTT (for IoT scenarios)

**Message Format:**
```json
{
  "messageId": "uuid",
  "timestamp": "ISO8601",
  "messageType": "customer.verification.request",
  "correlationId": "uuid",
  "payload": { ... },
  "headers": {
    "source": "system-id",
    "priority": "high"
  }
}
```

---

## 3. Data Exchange Patterns

### 3.1 Synchronous Request-Response

For immediate operations:
```
Client -> POST /api/v1/screening -> Server
Client <- 200 OK + Results <- Server
```

### 3.2 Asynchronous Processing

For long-running operations:
```
Client -> POST /api/v1/cdd -> Server
Client <- 202 Accepted + JobID <- Server

Client -> GET /api/v1/cdd/{jobId} -> Server
Client <- 200 OK + Status <- Server
```

### 3.3 Event-Driven Architecture

```
System A -> Publish Event -> Message Queue
Message Queue -> Notify -> System B
System B -> Process -> Update Database
System B -> Publish Result -> Message Queue
```

---

## 4. Data Synchronization

### 4.1 Full Synchronization

Complete dataset transfer:
```
POST /api/v1/sync/full
{
  "syncType": "full",
  "entities": ["customers", "transactions"],
  "since": null
}
```

### 4.2 Incremental Synchronization

Delta updates only:
```
POST /api/v1/sync/incremental
{
  "syncType": "incremental",
  "entities": ["customers"],
  "since": "2025-12-24T00:00:00Z",
  "limit": 1000
}
```

### 4.3 Change Data Capture (CDC)

Real-time change streaming:
```
Stream: /api/v1/stream/changes

Event: INSERT
{
  "operation": "INSERT",
  "table": "customers",
  "data": { ... },
  "timestamp": "2025-12-25T10:00:00Z"
}

Event: UPDATE
{
  "operation": "UPDATE",
  "table": "customers",
  "before": { ... },
  "after": { ... },
  "timestamp": "2025-12-25T10:01:00Z"
}
```

---

## 5. File Transfer Protocols

### 5.1 SFTP/FTPS

For bulk file transfers:
```
Server: sftp://secure.kyc-aml.example.com
Port: 22
Authentication: SSH Key + Password

Directory Structure:
/incoming/
/processed/
/errors/
/archive/
```

### 5.2 Batch File Formats

**CSV Format:**
```csv
customer_id,first_name,last_name,dob,risk_rating
uuid-1,John,Smith,1980-01-15,low
uuid-2,Jane,Doe,1985-03-22,medium
```

**XML Format:**
```xml
<?xml version="1.0" encoding="UTF-8"?>
<CustomerBatch>
  <Customer>
    <CustomerId>uuid-1</CustomerId>
    <FirstName>John</FirstName>
    <LastName>Smith</LastName>
    <DateOfBirth>1980-01-15</DateOfBirth>
    <RiskRating>low</RiskRating>
  </Customer>
</CustomerBatch>
```

---

## 6. Blockchain Integration Protocol

### 6.1 Distributed Ledger for Audit Trails

```javascript
// Store verification hash on blockchain
POST /api/v1/blockchain/store
{
  "recordType": "cdd_verification",
  "recordId": "uuid",
  "dataHash": "sha256_hash",
  "timestamp": "2025-12-25T10:00:00Z"
}

Response:
{
  "blockchainTxId": "0x123...",
  "blockNumber": 12345,
  "confirmations": 0
}

// Verify record authenticity
GET /api/v1/blockchain/verify/{recordId}
Response:
{
  "verified": true,
  "blockchainTxId": "0x123...",
  "storedHash": "sha256_hash",
  "currentHash": "sha256_hash",
  "match": true
}
```

### 6.2 Smart Contract Integration

```solidity
// KYC Registry Smart Contract
contract KYCRegistry {
  struct KYCRecord {
    bytes32 recordHash;
    uint256 timestamp;
    address verifier;
    bool isValid;
  }
  
  mapping(bytes32 => KYCRecord) public records;
  
  function registerKYC(bytes32 customerId, bytes32 recordHash)
    public returns (bool) {
    records[customerId] = KYCRecord({
      recordHash: recordHash,
      timestamp: block.timestamp,
      verifier: msg.sender,
      isValid: true
    });
    return true;
  }
  
  function verifyKYC(bytes32 customerId)
    public view returns (bool, uint256) {
    KYCRecord memory record = records[customerId];
    return (record.isValid, record.timestamp);
  }
}
```

---

## 7. Inter-System Communication

### 7.1 Service Mesh Integration

Using Istio/Linkerd:
```yaml
apiVersion: v1
kind: Service
metadata:
  name: kyc-service
  annotations:
    service.istio.io/canonical-name: kyc
spec:
  ports:
  - port: 8080
    name: http
  selector:
    app: kyc
```

### 7.2 Circuit Breaker Pattern

```javascript
const circuitBreaker = {
  failureThreshold: 5,
  successThreshold: 2,
  timeout: 60000,
  resetTimeout: 30000
};

function callWithCircuitBreaker(endpoint) {
  if (circuit.isOpen()) {
    return fallbackResponse();
  }
  
  try {
    const response = await fetch(endpoint);
    circuit.recordSuccess();
    return response;
  } catch (error) {
    circuit.recordFailure();
    throw error;
  }
}
```

---

## 8. Data Validation Protocol

### 8.1 Request Validation

```json
{
  "validationRules": {
    "customerName": {
      "type": "string",
      "minLength": 1,
      "maxLength": 100,
      "pattern": "^[A-Za-z\\s'-]+$"
    },
    "dateOfBirth": {
      "type": "date",
      "format": "ISO8601",
      "min": "1900-01-01",
      "max": "today-18years"
    },
    "email": {
      "type": "email",
      "required": true
    }
  }
}
```

### 8.2 Response Validation

Clients must validate:
- Schema compliance
- Data type correctness
- Business rule adherence
- Signature verification (if signed)

---

## 9. Caching Strategy

### 9.1 Cache Headers

```
Cache-Control: private, max-age=3600
ETag: "33a64df551425fcc55e4d42a148795d9f25f89d4"
Last-Modified: Wed, 25 Dec 2025 10:00:00 GMT

// Conditional request
If-None-Match: "33a64df551425fcc55e4d42a148795d9f25f89d4"
Response: 304 Not Modified
```

### 9.2 Cache Invalidation

```
POST /api/v1/cache/invalidate
{
  "resource": "/customers/{customerId}",
  "reason": "data_update"
}
```

---

## 10. Monitoring & Observability

### 10.1 Health Check Protocol

```
GET /health
Response 200 OK:
{
  "status": "healthy",
  "version": "1.0.0",
  "dependencies": {
    "database": "healthy",
    "cache": "healthy",
    "messageQueue": "healthy"
  },
  "timestamp": "2025-12-25T10:00:00Z"
}
```

### 10.2 Metrics Endpoint

```
GET /metrics
Content-Type: text/plain

# HELP api_requests_total Total API requests
# TYPE api_requests_total counter
api_requests_total{method="POST",endpoint="/customers"} 1234

# HELP api_request_duration_seconds API request duration
# TYPE api_request_duration_seconds histogram
api_request_duration_seconds_bucket{le="0.1"} 823
api_request_duration_seconds_bucket{le="0.5"} 1200
```

### 10.3 Distributed Tracing

Using OpenTelemetry:
```javascript
const tracer = trace.getTracer('kyc-service');

const span = tracer.startSpan('process_customer_verification');
span.setAttribute('customer.id', customerId);
span.setAttribute('verification.type', 'enhanced');

try {
  const result = await verifyCustomer(customerId);
  span.setStatus({ code: SpanStatusCode.OK });
  return result;
} catch (error) {
  span.setStatus({ 
    code: SpanStatusCode.ERROR,
    message: error.message 
  });
  throw error;
} finally {
  span.end();
}
```

---

## 11. Compliance Protocols

### 11.1 Audit Logging

Every operation must generate audit log:
```json
{
  "auditId": "uuid",
  "timestamp": "2025-12-25T10:00:00Z",
  "userId": "uuid",
  "action": "customer.update",
  "resourceType": "customer",
  "resourceId": "uuid",
  "changes": {
    "field": "address",
    "oldValue": "...",
    "newValue": "..."
  },
  "ipAddress": "192.168.1.1",
  "userAgent": "...",
  "result": "success"
}
```

### 11.2 Data Retention

```json
{
  "retentionPolicy": {
    "customerData": "5 years after relationship end",
    "transactionData": "7 years",
    "sarReports": "10 years",
    "auditLogs": "indefinite"
  }
}
```

---

## 12. Disaster Recovery

### 12.1 Backup Protocol

- **Frequency:** Continuous (CDC) + Daily full backups
- **Retention:** 30 days point-in-time recovery
- **Testing:** Monthly recovery drills
- **Encryption:** AES-256 for backups at rest

### 12.2 Failover Protocol

```
Primary Site Failure Detection
  ↓
Automatic DNS Failover (60 seconds)
  ↓
Secondary Site Activation
  ↓
Data Synchronization Verification
  ↓
Service Restoration
```

---

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Classification: Public  
Distribution: Unrestricted  
© 2025 WIA (World Certification Industry Association)