I previously worked for an international company that manufactures hinges for heavy doors. I once spoke with a man who worked with locks. He said,(and I don't recall the jargon) [keys will soon have more than one set of teeth and the angle between the rows of teeth will be variable].
Do you remember when this was? Multiple rows of pins have been around for ... well, since 1848 at least, but in modern locks, Kaba & Sargent (later bought by Kaba) have been using multiple rows for many decades.
Doesn't actually prevent bumping, though! Additionally, the "angle between the rows" is interesting in thinking what exactly he might have said. Sargent, again, with the Keso introduced the idea of somewhat variable spacing of the pins in the Keso.
Additionally, if we're talking angles, there was the Medeco Biaxial (often confused for the original Medeco lock) which introduced the idea of "fore", "center" and "aft" positioning of the cuts in the key/position of the chiseled tips of the pins.
The former, Sargent, can still be readily bumped as even though you won't always know if a pin will be present, you know every possible location of the pins and can adjust accordingly. With Medeco, it's significantly harder, though they caused themselves problems with a heavily restricted code book so that the mere visual observation of the first two pins in the lock could give you a very good idea of the positing of the other elements and allow you to make a few possible bump keys to attack them. They've since fixed that problem.
