Signed Dual-Slot OTA Needed an Acceptance State, Not Just a Boot Flag
A new image should become permanent only after the device proves it can boot, verify, connect and report healthy.
ECDSA
Signed Firmware Changed OTA from File Delivery into a Trust Decision
A device should decide whether firmware is authorized, not merely whether the download completed successfully.
ECDSA Signing Makes the Device Verify Who Produced the Firmware
Transport security alone does not prove an artifact should be trusted after download.