Figure 1:
Communication in a symmetric system.
Figure 2:
Communication in an asymmetric system.
Figure 3:
Examples of pin organization in a mechanical lock a) with one opening key b) with two opening keys.
Figure 4:
Hierarchy of keys in a master-key system.
Figure 5:
Externally tangent circles.
Figure 6:
Way of organizing keys in the master-key technique.
Figure 7:
An example of related objects.
Figure 8:
Example of shifting two points of a linear function.