Implementing Privacy-Compliant Integration Architecture

Implementing Privacy-Compliant Integration Architecture

Building privacy-compliant integrations starts with architectural decisions that minimize data exposure. Rather than sharing raw user data, consider whether aggregated, anonymized, or pseudonymized data would suffice. Implement data minimization at the integration layer, sharing only necessary fields for specific functionality. Design integrations that keep sensitive data within your control while still enabling third-party features.

// Privacy-focused third-party integration manager
class PrivacyCompliantIntegrationManager {
  constructor() {
    this.integrations = new Map();
    this.dataFilters = new Map();
    this.consentManager = new ConsentManager();
    this.auditLogger = new AuditLogger();
  }

  // Register third-party integration with privacy controls
  registerIntegration(config) {
    const integration = {
      id: config.id,
      name: config.name,
      purpose: config.purpose,
      dataCategories: config.dataCategories,
      legalBasis: config.legalBasis,
      dataRetention: config.dataRetention,
      privacyControls: {
        minimization: config.minimization || 'strict',
        anonymization: config.anonymization || false,
        encryption: config.encryption || 'required',
        audit: config.audit || 'comprehensive'
      },
      contractualTerms: config.contractualTerms
    };

    // Create data filter for this integration
    const filter = this.createDataFilter(integration);
    this.dataFilters.set(config.id, filter);
    
    // Register integration
    this.integrations.set(config.id, integration);
    
    // Set up monitoring
    this.setupIntegrationMonitoring(integration);
    
    return integration;
  }

  // Create data filter based on privacy requirements
  createDataFilter(integration) {
    return {
      // Define allowed fields for this integration
      allowedFields: this.determineAllowedFields(integration),
      
      // Transform functions for minimization
      transformers: {
        email: (value) => {
          if (integration.privacyControls.anonymization) {
            return this.hashEmail(value);
          }
          return value;
        },
        
        ipAddress: (value) => {
          if (integration.purpose === 'analytics') {
            return this.anonymizeIP(value);
          }
          return value;
        },
        
        userId: (value) => {
          if (integration.privacyControls.anonymization) {
            return this.generatePseudonym(value);
          }
          return value;
        },
        
        location: (value) => {
          if (integration.privacyControls.minimization === 'strict') {
            return { country: value.country }; // Remove detailed location
          }
          return value;
        }
      },
      
      // Validation functions
      validators: {
        consent: () => this.validateConsent(integration),
        purpose: (purpose) => integration.purpose.includes(purpose),
        retention: () => this.checkRetentionCompliance(integration)
      }
    };
  }

  // Send data to third party with privacy controls
  async sendToThirdParty(integrationId, data, purpose) {
    const integration = this.integrations.get(integrationId);
    if (!integration) {
      throw new Error(`Unknown integration: ${integrationId}`);
    }

    try {
      // Check consent
      const hasConsent = await this.checkConsent(integration, data.userId);
      if (!hasConsent && integration.legalBasis === 'consent') {
        throw new Error('User consent required for this integration');
      }

      // Filter and transform data
      const filter = this.dataFilters.get(integrationId);
      const filteredData = this.applyDataFilter(data, filter);
      
      // Add privacy metadata
      const enrichedData = {
        ...filteredData,
        _privacy: {
          purpose,
          timestamp: new Date().toISOString(),
          dataSubjectId: this.generateDataSubjectId(data.userId),
          consentId: hasConsent ? hasConsent.consentId : null
        }
      };
      
      // Encrypt if required
      const payload = integration.privacyControls.encryption === 'required' 
        ? await this.encryptPayload(enrichedData, integration)
        : enrichedData;
      
      // Send data
      const response = await this.transmitData(integration, payload);
      
      // Log transmission
      await this.logDataTransmission({
        integrationId,
        purpose,
        dataCategories: this.identifyDataCategories(filteredData),
        timestamp: new Date().toISOString(),
        success: true,
        responseId: response.id
      });
      
      return response;
    } catch (error) {
      await this.handleTransmissionError(integration, error);
      throw error;
    }
  }

  // Apply data filtering and transformation
  applyDataFilter(data, filter) {
    const filtered = {};
    
    for (const [key, value] of Object.entries(data)) {
      // Check if field is allowed
      if (!filter.allowedFields.includes(key)) {
        continue;
      }
      
      // Apply transformation if exists
      if (filter.transformers[key]) {
        filtered[key] = filter.transformers[key](value);
      } else {
        filtered[key] = value;
      }
    }
    
    return filtered;
  }

  // Set up real-time monitoring for integration
  setupIntegrationMonitoring(integration) {
    // Monitor data volume
    this.monitorDataVolume(integration.id);
    
    // Monitor for unexpected data categories
    this.monitorDataCategories(integration.id);
    
    // Monitor third-party compliance
    this.monitorThirdPartyCompliance(integration);
    
    // Set up alerts
    this.setupComplianceAlerts(integration);
  }

  // Monitor data volume to detect anomalies
  monitorDataVolume(integrationId) {
    const monitor = new DataVolumeMonitor({
      integrationId,
      thresholds: {
        hourly: 10000,
        daily: 200000,
        unusual_spike: 5 // 5x normal volume
      },
      actions: {
        threshold_exceeded: async (metric) => {
          await this.pauseIntegration(integrationId);
          await this.alertPrivacyTeam({
            type: 'volume_anomaly',
            integration: integrationId,
            metric
          });
        }
      }
    });
    
    monitor.start();
  }
}

// Privacy-aware API gateway for third parties
class PrivacyAwareAPIGateway {
  constructor() {
    this.rateLimiter = new RateLimiter();
    this.privacyProxy = new PrivacyProxy();
    this.responseFilter = new ResponseFilter();
  }

  // Create privacy-preserving API endpoint
  createEndpoint(config) {
    return async (req, res) => {
      try {
        // Validate request
        const validation = await this.validateRequest(req, config);
        if (!validation.valid) {
          return res.status(400).json({ error: validation.error });
        }
        
        // Check rate limits
        const rateLimitOk = await this.rateLimiter.check(req, config);
        if (!rateLimitOk) {
          return res.status(429).json({ error: 'Rate limit exceeded' });
        }
        
        // Apply privacy transformations
        const transformedRequest = await this.privacyProxy.transform(req, config);
        
        // Forward to third party
        const response = await this.forwardRequest(transformedRequest, config);
        
        // Filter response
        const filteredResponse = await this.responseFilter.filter(response, config);
        
        // Log for audit
        await this.logAPICall({
          endpoint: config.endpoint,
          method: req.method,
          dataShared: this.summarizeDataShared(transformedRequest),
          timestamp: new Date().toISOString()
        });
        
        res.json(filteredResponse);
      } catch (error) {
        this.handleAPIError(error, res);
      }
    };
  }

  // Privacy proxy for request transformation
  async transformRequest(req, config) {
    const transformed = { ...req };
    
    // Remove or transform sensitive fields
    if (config.removeSensitiveFields) {
      config.sensitiveFields.forEach(field => {
        delete transformed.body[field];
      });
    }
    
    // Apply field-level encryption
    if (config.encryptFields) {
      for (const field of config.encryptFields) {
        if (transformed.body[field]) {
          transformed.body[field] = await this.encryptField(
            transformed.body[field],
            config.encryptionKey
          );
        }
      }
    }
    
    // Add privacy headers
    transformed.headers = {
      ...transformed.headers,
      'X-Privacy-Mode': config.privacyMode || 'strict',
      'X-Data-Categories': this.identifyDataCategories(transformed.body).join(','),
      'X-Purpose': config.purpose
    };
    
    return transformed;
  }
}