Question about asymmetric encryption DFU

[Eugene]

We have created a firmware and encrypted it with a private key and made it public. When we download it to the chip it's decrypted with a public key stored in the chip. Right? What adnventages does it offer vs. standart symmetric encryption?

[Vidar Berg]

DFU signing ensures that an image is received from a trusted source, but doesn't encrypt it as Wojtek mentioned. The advantage with asymmetric over symmetric signing is that it's safer because only the public key will be stored on the nRF device, while the drawback is increased complexity.