In accordance with an embodiment, a method for managing a memory within a system-on-a-chip including a processor, a memory and a firewall device, includes: generating, by the processor, a request to access the memory, where the request has a access permission level; controlling, by the firewall device, access to the at least one memory region of the memory as a function of the access permission level of the request and a respective access permission level associated with at least one memory region; and erasing, by the firewall device, the at least one memory regions when its respective access permission level is modified, where erasing comprises performing a hardware-implemented erasure.