Case Study 4: Healthcare IoT Device Threat Modeling

A medical device manufacturer developing connected insulin pumps faced unique threat modeling challenges. The devices needed to balance security with life-critical functionality, usability for patients with varying technical skills, and battery life constraints. Their threat modeling journey illustrates addressing domain-specific requirements.

The threat modeling team included not just security experts but also medical professionals, patient advocates, and safety engineers. This diverse perspective revealed threats that pure technical analysis would miss: social engineering attacks targeting elderly patients, safety risks from security controls (e.g., authentication failures preventing emergency insulin delivery), and privacy concerns about glucose reading data.

Physical security threats proved particularly important. The threat model identified risks from device theft, tampering during shipping, and even customs inspections potentially compromising device integrity. This led to implementing secure boot, tamper-evident packaging, and encrypted configuration that survives battery replacement.

The team discovered that traditional CIA (Confidentiality, Integrity, Availability) prioritization didn't align with medical device requirements. Availability was paramount—a device that fails secure but prevents insulin delivery could kill patients. This led to developing fail-safe modes where critical functions operate even if security components fail, while logging events for later analysis.

Regulatory compliance added complexity, with threat modeling needing to satisfy both FDA safety requirements and emerging medical device security standards. The threat model became a living document updated with each reported vulnerability in similar devices, creating a feedback loop that improved security over the product lifecycle.