Data protection through address modification

An electronic system includes a secret value (e.g., an encryption key) which is used for its intended purpose after which the address translations in the system's memory management unit are modified to prevent further access to the secret value. The address translation modifications also include modification of a translation for the memory management unit itself thereby preventing further modification of the address translations. The secret value cannot again be accessed until the system is reinitialized, but the address translations are modified during each system initialization so that the secret value is only usable for its intended purpose during the initialization process. In other implementations, the system modifies mappings between physical addresses and hardware components to preclude further access to the secret value.