Dentatsuhouho (Communications)

In ancient times, information was carried basically by person to person, and therefore the information transmission speed was the same as walking speed. If the speed was important, ancient people used signals to send information. The media were sounds such as bells, drums, and gongs, beacon fire, and flags, In the case of the ninja, priority was given to communicating information to coagents unknown to third parties without failure rather than speed. For this reason, the ninja enciphered information. Primary ciphering techniques included the arrangement of pebbles included the arrangement of pebbles, broken twigs, and color combinations of scattered rice grains dyed blue, yellow, red, black, and purple, as well as knotted ropes hung under the eaves expressing “Come later” or “Heading north.”