Flash Encryption Planning
Protect code and sensitive data at rest using the MCU vendor’s supported encryption lifecycle.
Arduino-compatible frameworks, ESP-IDF/FreeRTOS, PIC/AVR/STM32/RP-class systems; apply exact vendor documentation for the selected MCU.Architecture
Protected key material → hardware flash decrypt/encrypt path → encrypted application/data partitions.
Security and recovery risks
- Encryption does not replace signed/authenticated firmware.nKey loss can make devices unrecoverable.nConfirm debugger/service impact before irreversible enablement.
Implementation procedure
- Map sensitive and non-sensitive partitions.nUnderstand development versus release encryption modes.nTest encrypted boot, update and recovery on disposable hardware.nSecure manufacturing key handling.nVerify readback and downgrade behaviour.
Starter code / configuration
Use vendor tooling; do not invent custom flash encryption.Verification evidence
| Test | Expected | Evidence |
|---|---|---|
| Nominal boot | Correct version and hardware revision reported | Captured boot log |
| Fault recovery | Defined safe state and reset reason | Fault-injection record |
| Power cycle | No corrupt configuration or unsafe output | Repeated-cycle log |
Required release artifacts
- Versioned firmware binary and SHA-256
- Source revision / build identifier
- Board and hardware-revision compatibility list
- Test report and known limitations
- Recovery image and factory-reset procedure
- Provisioning/calibration schema
- Release approval record
Local browser tools
Firmware production workbench
A/B update exercise
OTA and automatic rollback simulator
Advance one validated stage at a time. A failed boot test returns the device to the previous slot.
- Running confirmed firmware from Slot A.
Release gate
Production-readiness checklist
A downloadable release decision is generated only after every mandatory control is confirmed.