We are talking about having physical access to the machine for long enough to partially dissasemble it and physically manipulate the mother board. There are a l

We are talking about having physical access to the machine for long enough to partially dissasemble it and physically manipulate the mother board. There are a lot of attacks that enables, and almost no one even claims to defend against them. Put another way, a modern computer can be thought if as a network of relativity simple devices, of which the eeprom is one. Normally we assume that an attacker does not have access to this network. If the attacker does have access to this network, the game is lost. Everything about the network is unencrypted.