...bypassing his DRM featured house...
Wouldn't that be more like ARM-featured house, as in Analog Rights Management?
This is a worst case solution since it would imply that the brain is not understood yet.
That's not too bad. When we build one of those, we can afford it with a probe facility that it can use to observe and manipulate its own brain or clones thereof. It can then find out how its brain works and tell us, or code up a minimal AI if we want that.
"Something you know" isn't what counts when it comes to protecting you from self incrimination; it is whether the "something you know" is incriminating you.
This leads to an interesting idea. Claim that you passphrase is a confession. If you plan ahead, you can even make that claim true. Encrypt your plan to assassinate the president with "I plan to assassinate the president OV:}A7MC".
"They that can give up essential liberty to obtain a little temporary saftey deserve neither liberty not saftey." -- Benjamin Franklin, 1759