Physical and firmware attacks on the enforcing hardware

RAND's threat analysis includes invasive and semi-invasive physical attacks, fault injection, and firmware and supply-chain attacks. It judges that anti-tamper measures would not be insurmountable for a determined and well-resourced adversary ². Ma et al. assume that neither the model nor human attackers can alter on-chip hardware ¹. Petrie's design aims to raise the cost of invasive editing by spreading thousands of security blocks through the chip, so that an attack would need thousands of precise edits per chip ⁷.