The present invention relates to key management in a secure microcontroller, and more particularly, to systems, devices and methods of automatically and transparently employing logic or physical address based keys that may also be transferred using dedicated buses. A cryptographic engine translates a logic address to at least one physical address, and processes a corresponding data word based on at least one target key. The target key is selected from a plurality of keys based on the logic or physical address. A universal memory controller stores each processed data word in the corresponding physical address within a memory. Each key is associated with a memory region within the memory, and therefore, the logic or physical address associated with a memory region may be used to automatically identify the corresponding target key. A dedicated secure link may be used to transport key request commands and the plurality of keys.