Designing a Healthcare Data Platform

Healthcare systems must balance performance with strict HIPAA compliance requirements for Protected Health Information (PHI).

HIPAA Requirements

Privacy Rule:  Control access to PHI
Security Rule: Technical safeguards for electronic PHI
Breach Rule:   Notification within 60 days of breach

PHI Data Categories

PHI includes: Name, DOB, Address, SSN, Medical Record #,
              Health conditions, Treatment, Payment info

Encryption

At rest: AES-256 (database, S3)
In transit: TLS 1.3
Field level: Encrypt PHI columns individually
Key management: AWS KMS / HashiCorp Vault

Never log PHI in plain text

Access Control

Role-Based:
  Doctor     → Read/write own patients
  Nurse      → Read assigned patients
  Admin      → Billing data only
  Researcher → De-identified data only
  Patient    → Own records only

Break-glass: Emergency access with mandatory audit

Audit Logging

Every PHI access must be logged:

{
  "timestamp": "2026-03-18T10:00:00Z",
  "user_id": "doctor_123",
  "action": "VIEW",
  "resource": "patient_record",
  "patient_id": "[HASH]",
  "reason": "treatment",
  "ip": "10.0.0.1"
}

Audit logs immutable, retained 6+ years.

De-Identification

Research datasets: Remove all 18 HIPAA identifiers.

# Safe Harbor method
remove: name, zip, dates, age > 89, etc.
replace: zip → first 3 digits if population > 20K

Interoperability (FHIR)

HL7 FHIR (Fast Healthcare Interoperability Resources):

Standard API for health data exchange
GET /fhir/Patient/123
GET /fhir/Observation?patient=123&code=glucose

Consent Management

Patient controls who sees their data:
  Grant access to Dr. Smith until Dec 2026
  Revoke access from Dr. Jones
  Allow research use (anonymized only)

Conclusion

Healthcare systems prioritize security and compliance over performance. Encryption, RBAC, immutable audit logs, and FHIR interoperability are non-negotiable requirements.