Any way to avoid hardcoded private decryption key?

[OlegZv]

Seems like the private decryption key is currently hardcoded in the MCUboot build. Is there any way to avoid that? MCUboot supports retrieving the public key for signature validation from KMU, can it also use KMU for private key retrieval? Thank you for any responses.

There are a lot of issues and PRs regarding this, but none of them seem to point to a tangible solution or a workaround. A few closely related:

• Zephyr: Encryption keys are hardcoded - No way to override? #1268
• boot: zephyr: User defined encryption key #1088 (closed, not merged)
• Fix Insufficient image encryption feature #596 (closed, not merged)