Hello,
I am interested in the optional decryption sequence part of secure boot on STM32N6 mcu. As described in UM3234 (How to proceed with boot ROM on STM32N6 MCUs) a key derivation function is used to produce an encryption key. However I am not sure how the Enc/Dec Master Key is produced, as in the OTP mapping table (RM0486: STM32N6 Reference Manual) only an EDMK derivation constant is present. Am I correct to assume that this OTP168 word is used to derive the EDMK out of OEM secret (OTP 364-367)? If so, what's the algorithm? Additionally, what's the derivation constant used in ROM that's mentioned in the diagram? Is it publicly available?
Thanks,
kradzphsys
