Engineering · Security Architecture

Security Architecture

A technical overview of Travi's security posture — covering network topology, data protection, threat model, access controls, and compliance certifications. Designed to support hospital IT security reviews and investor due diligence.

TRAVI AI AGENT · SECURITY Network & Security Architecture INTERNET Hospital EHR Patient SMS 🖥️ Clinician UI PERIMETER 🛡️ WAF AWS Shield + CloudFront CDN / DDoS TLS 1.3 enforced AWS VPC — us-east-1 PUBLIC SUBNET 🚪 API Gateway Rate limit · JWT auth ⚖️ ALB Application Load Balancer PRIVATE SUBNET — no public IPs App Servers ECS Fargate 🧠 AI Workers Lambda · async 📜 Audit Svc CloudTrail DATA SUBNET — encrypted at rest (AES-256) PHI Vault RDS · field-level enc. 🗄️ Outcome DB PostgreSQL · de-id 🗝️ Secrets Mgr AWS KMS · rotation 🪣 S3 Audit Logs Immutable · Glacier Automated daily backups · Cross-region replication (us-west-2) · RTO < 4h · RPO < 1h All data encrypted in transit (TLS 1.3) and at rest (AES-256) · KMS key rotation every 90 days COMPLIANCE & CERTIFICATIONS HIPAA BAA signed SOC 2 T2 In progress Q3 '26 FHIR R4 Certified SMART on FHIR Pen Test Annual · Q2 '26 GDPR Ready (EU expansion) Untrusted / internet zone Public subnet Private subnet (no public IP) Data subnet (encrypted at rest) Untrusted traffic Internal traffic

Threat Model & Controls

Threat Likelihood Control Status
PHI data breach HIGH AES-256 field-level encryption, PHI vault isolation, no PHI in logs, BAA with all vendors MITIGATED
API injection / SSRF MEDIUM WAF with OWASP ruleset, input validation at API Gateway, parameterized queries, SSRF blocklist MITIGATED
LLM prompt injection MEDIUM Structured output schema enforcement, 7-gate post-processing validation, human review flag for anomalous outputs MITIGATED
Credential compromise MEDIUM AWS Secrets Manager with auto-rotation, no hardcoded secrets, MFA enforced for all admin access, least-privilege IAM MITIGATED
DDoS / availability LOW AWS Shield Standard + Advanced, CloudFront CDN, auto-scaling ECS Fargate, rate limiting at API Gateway MITIGATED
Insider threat LOW Role-based access control, immutable audit log, no single person can access PHI vault + audit logs simultaneously, background checks MITIGATED
Third-party vendor breach MEDIUM BAA with all PHI-touching vendors (Twilio, OpenAI, AWS), annual vendor security review, data minimization — vendors receive de-identified data only MONITORED

Access Control Model

Patient

SMS only. No login, no account. Patient token is pseudonymous — no PII in the messaging layer. Consent captured via SMS reply.

Care Coordinator

SSO via hospital IdP (SAML 2.0). Read access to assigned patient cohort only. Cannot access PHI vault directly. MFA required.

Physician

Receives alerts in EHR in-basket only. No Travi login required. All interactions logged via FHIR Communication resource write-back.

Hospital Admin

Read-only analytics API access. Can query aggregate outcomes and HRRP metrics. No access to individual patient records. Scoped JWT tokens.

Travi Engineering

Zero standing access to production PHI. Break-glass access requires dual approval + is logged immutably. Prod access reviewed quarterly.

Compliance Officer

Read-only access to audit logs and access reports. Can trigger access reviews. Cannot modify data. Separate audit-only IAM role.

Penetration Testing & Vulnerability Management

Annual third-party penetration test conducted by a CREST-certified firm. Most recent test: Q2 2026 — zero critical findings, two medium findings (both remediated within 14 days). Continuous vulnerability scanning via AWS Inspector and Snyk on all container images and dependencies. CVE patching SLA: critical within 24h, high within 7 days.

See also: FHIR R4 Data Flow — for how PHI moves through the pipeline, and Product Cycle Diagram — for the end-to-end episode execution flow.