Your understanding of how flash encryption works in Release mode is correct, but development mode is not secure and is not suitable for your use casebonmotwang wrote: ↑Fri Mar 06, 2020 4:49 pmAfter reading more about the encryption.
Development Mode should work for me.
In development mode, it's possible to upload new code which runs on the device (as the encryption happens inside the ESP32 during the upload process, using the secret key). An attacker can upload a small bootloader program that dumps the rest of the flash contents to UART (decrypted, because this is running in the bootloader mode) or otherwise releases it.
For production use, you need to enable flash encryption in Release Mode.
Angus