Healthcare Email Validation: HIPAA Compliance Guide for Patient Communication 2025

// HIPAA-Compliant Email Validation Implementation
import crypto from 'crypto';

class HealthcareEmailValidator {
  constructor(apiKey, baaVerification) {
    this.apiKey = apiKey;
    this.baaVerified = baaVerification;
    this.encryptionKey = process.env.HIPAA_ENCRYPTION_KEY;
    this.auditLog = [];

    // Verify BAA status before initialization
    if (!this.baaVerified) {
      throw new Error('Business Associate Agreement required for PHI processing');
    }
  }

  // Validate patient email with HIPAA compliance
  async validatePatientEmail(email, patientId, context = {}) {
    const validationId = this.generateValidationId();
    const startTime = Date.now();

    try {
      // Log validation request without PHI
      this.logValidationEvent({
        validationId,
        timestamp: new Date().toISOString(),
        action: 'validation_started',
        patientId: this.hashPatientId(patientId), // Hash patient identifiers
        emailHash: this.hashEmail(email),
        context: this.sanitizeContext(context)
      });

      // Encrypt email for transmission
      const encryptedEmail = this.encryptEmail(email);

      const response = await fetch('https://api.email-check.app/v1/healthcare/validate', {
        method: 'POST',
        headers: {
          'Content-Type': 'application/json',
          'Authorization': `Bearer ${this.apiKey}`,
          'X-HIPAA-BAA': 'verified',
          'X-Validation-ID': validationId,
          'X-Request-Timestamp': new Date().toISOString()
        },
        body: JSON.stringify({
          encrypted_email: encryptedEmail,
          healthcare_mode: true,
          audit_logging: true,
          no_phi_storage: true
        })
      });

      if (!response.ok) {
        throw new Error(`Validation failed: ${response.status}`);
      }

      const result = await response.json();
      const processingTime = Date.now() - startTime;

      // Log successful validation
      this.logValidationEvent({
        validationId,
        timestamp: new Date().toISOString(),
        action: 'validation_completed',
        processingTime,
        result: this.sanitizeValidationResult(result)
      });

      return {
        ...result,
        validationId,
        hipaaCompliant: true,
        processingTime: `${processingTime}ms`,
        auditTrail: validationId
      };

    } catch (error) {
      // Log validation error
      this.logValidationEvent({
        validationId,
        timestamp: new Date().toISOString(),
        action: 'validation_failed',
        error: error.message,
        noPhiExposed: true
      });

      // Don't expose PHI in error messages
      throw new Error('Email validation failed. Please try again or contact support.');
    }
  }

  // HIPAA security methods
  encryptEmail(email) {
    const cipher = crypto.createCipher('aes-256-gcm', this.encryptionKey);
    let encrypted = cipher.update(email, 'utf8', 'hex');
    encrypted += cipher.final('hex');
    return encrypted;
  }

  hashPatientId(patientId) {
    return crypto.createHash('sha-256').update(patientId).digest('hex');
  }

  hashEmail(email) {
    return crypto.createHash('sha-256').update(email).digest('hex');
  }

  generateValidationId() {
    return `val_${Date.now()}_${crypto.randomBytes(16).toString('hex')}`;
  }

  logValidationEvent(event) {
    // Store audit logs securely (encrypted, access-controlled)
    this.auditLog.push({
      ...event,
      timestamp: new Date().toISOString(),
      serverId: process.env.SERVER_ID || 'unknown'
    });

    // Immediate log to secure audit system
    this.sendToAuditLog(event);
  }

  sanitizeContext(context) {
    // Remove any PHI from context data
    const sanitized = { ...context };
    delete sanitized.patientName;
    delete sanitized.medicalRecord;
    delete sanitized.diagnosis;
    return sanitized;
  }
}