A medeco (like a biaxial or m3) has 2, namely z-axis and rotation. But they have separate mechanical processes. So, you pick to shear line, then pick the sidebar.
In a medeco cam lock you have 2 degrees of movement that aren't separate. You have to lift and rotate at the same time since the mechanical mechanism is the same for both (there is a slot in the pin to let the sidebar in)
Which leads me to think that you could develop a system with 3 degrees of freedom (say z,rotation and x) or even 4 (x,y,z, and rotation) (or up to 6 if you want to get really crazy)
My first idea involves using a spherical "pin"

The slot on the front (which should be more to the side) would allow a side bar to drop. The pin has freedom of movement in the z-axis ( it would be held by a spring in a driverless sidebar arrangement). It has freedom of rotation around the z and y axis, where z is up and down, y is left and right and, and x is the direction the key is inserted. I imagine the key would look something like a laser cut key, with the grooves being variable depth.
You would have to limit the motion somewhat. I haven't figured out the details. And the thing would be a nightmare to produce. But, if we can find an efficient way to increase the degrees of freedom per locking element I think it would make mechanical locks that much more difficult to pick.