Comparison guide
Black-Box vs White-Box Pen Test
What you give the tester decides what they will find.
Side-by-side breakdown
| Dimension | Black-box | White-box |
|---|---|---|
| Info given to tester | Just the device and its external interfaces. | Source code, threat model, design docs, SBOM, credentials. |
| Simulates | External attacker with zero insider knowledge. | Informed adversary who has compromised internal documents or staff. |
| Coverage | Strong on external-facing attack surface; limited on internal logic. | Comprehensive - finds logic and design flaws unreachable from outside. |
| Effort | 2-4 weeks typical. | 4-8 weeks; cheaper per finding due to higher signal. |
| FDA expectation | Acceptable for some external interfaces but rarely sufficient on its own. | Preferred for the full cybersecurity testing report; aligns with AAMI SW96. |
| When to choose | Sanity-check a release candidate; vendor due diligence. | Premarket submission; deficiency-letter response; PMA support. |
When to use which
Default to white-box or gray-box testing for any premarket submission. Provide the testers with the threat model, SBOM, design docs, and a non-production credential set so they can verify each documented control.
Use black-box testing later in the lifecycle as a periodic external-attacker check (e.g. annually or after major releases), not as the primary premarket evidence.
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