[throwaway14356]

I loved the way the puzzle was presented in that video and loved the partial solution. It has been consuming idle brain cycles eversince.

First we should proudly make the key flat as security by obscurity is not done. We should solve the problem for real and it has to be easy to manufacture.

The real idea: put a tube around the cylinder. after rotating the cylinder by 45 deg it drags the tube along.

  [cylinder][ tube ][case
   key]||||||||[   ][     ]////
  [cylinder][ tube ][case

you have a pin in the tube with small discs on the key side. The inner cylinder can rotate freely for 45 degrees at which point it drags the tube along IF the pin is in the correct position thereby testing the correctness of the key used therein all pins simultaneously.

different keys can be had by changing the number of discs. No machining required.

Have fun

[throwaway14356]

Extra funny would be a second tube with a clock mechanism that delays a second attempt if the wrong key is used.

(Going to implement that one on all my enter password pages.)