docs/adr/010-security-compliance.md

ADR-010: HIPAA Compliance Strategy

Status

Accepted

Context

MediGuard AI processes Protected Health Information (PHI) and must comply with HIPAA (Health Insurance Portability and Accountability Act) requirements. Key compliance needs include:

• Data encryption at rest and in transit
• Access controls and audit logging
• Data minimization and retention policies
• Business Associate Agreement (BAA) with cloud providers
• Secure development practices

Decision

Implement a comprehensive HIPAA compliance strategy:

1. Data Protection

• Encryption: AES-256 encryption for data at rest, TLS 1.3 for data in transit
• Key Management: Use AWS KMS or similar for key rotation
• Data Masking: Mask PHI in logs and monitoring
• Minimal Data Storage: Only store necessary PHI with automatic deletion

2. Access Controls

• Authentication: Multi-factor authentication for admin access
• Authorization: Role-based access control (RBAC)
• Audit Logging: Comprehensive audit trail for all data access
• Session Management: Secure session handling with timeouts

3. Infrastructure Security

• Network Security: VPC with private subnets, security groups
• Container Security: Non-root containers, security scanning
• Secrets Management: AWS Secrets Manager or HashiCorp Vault
• Backup Security: Encrypted backups with secure retention

4. Development Practices

• Code Review: Security-focused code reviews
• Static Analysis: Automated security scanning (Bandit, Semgrep)
• Dependency Scanning: Regular vulnerability scans
• Penetration Testing: Annual security assessments

Consequences

Positive

• Compliance: Meets HIPAA requirements for healthcare data
• Trust: Builds trust with healthcare providers and patients
• Security: Robust security posture beyond HIPAA minimums
• Market: Enables entry into healthcare market
• Risk: Reduced risk of data breaches and penalties

Negative

• Complexity: Additional security measures increase complexity
• Cost: Higher infrastructure and compliance costs
• Performance: Security measures may impact performance
• Development: Slower development due to security requirements

Implementation

Encryption Example

class PHIEncryption:
    def __init__(self, key_manager):
        self.key_manager = key_manager
        
    def encrypt_phi(self, data: str) -> str:
        key = self.key_manager.get_latest_key()
        return AES.encrypt(data, key)
        
    def decrypt_phi(self, encrypted_data: str) -> str:
        key_id = extract_key_id(encrypted_data)
        key = self.key_manager.get_key(key_id)
        return AES.decrypt(encrypted_data, key)

Audit Logging

class HIPAAAuditMiddleware:
    async def log_access(self, user_id: str, resource: str, action: str):
        audit_entry = {
            "timestamp": datetime.utcnow(),
            "user_id": self.hash_user_id(user_id),
            "resource": resource,
            "action": action,
            "ip_address": self.get_client_ip()
        }
        await self.audit_logger.log(audit_entry)

Data Minimization

class DataRetentionPolicy:
    def __init__(self):
        self.retention_periods = {
            "analysis_results": timedelta(days=365),
            "user_sessions": timedelta(days=30),
            "audit_logs": timedelta(days=2555)  # 7 years
        }
    
    async def cleanup_expired_data(self):
        for data_type, retention in self.retention_periods.items():
            cutoff = datetime.utcnow() - retention
            await self.delete_data_before(data_type, cutoff)

Notes

• All cloud providers must sign BAAs
• Regular compliance audits (at least annually)
• Incident response plan for data breaches
• Employee training on HIPAA requirements
• Business continuity planning for disaster recovery
• Legal review of all compliance measures