Abstract: In an embodiment, a System-on-Chip (SoC) may include: a plurality of core domains, and a memory coupled to the plurality of core domains through a hardware firewall, wherein the hardware firewall is configured to enforce an adaptive Deny-By-Default (DBD) access policy in response to an event. In another embodiment, a circuit, may include: an access control policy generator configured to produce an adaptive DBD policy, and a hardware firewall coupled to the access control policy generator, the hardware firewall configured to enforce the adaptive DBD policy. In yet another embodiment, a method may include: storing an indication of a first DBD configuration state, the first DBD configuration state usable to enforce a first DBD access control policy, and changing the stored indication to a second DBD configuration state, the second DBD configuration state usable to enforce a second DBD access control policy.