DFU does not encrypt app_dfu_package.zip ???

[Mikhail]

I use SDK13, nRF52, S132

I use bootloader_secure_ble with generated public key for bootloader and for nrfutil. After all steps like discribed on devzone.nordicsemi.com/.../ I get app_dfu_package.zip wich should flash by air (DFU). I suppose, this .bin file should be encrypted. But If convert this .bin to hex (WinHex) I see same code like original file .hex ??? Is it normal? Where is encryption?

[grzegorz]

It's normal because there is no encryption. Keys are for digital signature, not for encryption. The goal is to prevent running untrusted code, not to protect your intellectual property.