The Covert Communication Methods of Ninja
How Ninja Passed On Messages
In ancient Japan, ninja couldn't rely on modern technology for communication—they had to get creative. Instead of sending texts or emails, these secretive spies used a range of clever and covert methods to pass along critical information without being caught.
One such technique was writing with invisible ink. According to Professor Yuji Yamada, a leading ninjutsu researcher, the ink was made from mashed soybean juice or unfiltered sake. Once dried, the words vanished, only to reappear when the message was held near fire, making it an ideal tool for ninja correspondence.
Smoke signals were another effective way to communicate over long distances. Ninja would create smoke by burning a mix of wolf dung and pine needles, and funnel it into the air using bamboo tubes. These signals worked best on clear days and allowed shinobi to send quick, coded messages across enemy lines.
Passwords were essential for identifying allies and maintaining secrecy. Ninja often used word-association passwords to confirm their identity. For instance, one would say "sun" and expect the response "moon." These seemingly simple exchanges kept sensitive information from falling into enemy hands.
Some common word-association passwords included:
- Flower — petal
- Smoke — fire
- Mountain — forest
- Sea — salt
Another ingenious method was using colored rice as signals. Ninja would dye rice grains in shades of blue, yellow, red, black, and purple, arranging them in specific patterns on roads to indicate directions or meeting points for comrades. The dye also served as a deterrent for birds, preventing them from eating the rice and disrupting the message.
Ninja also used rope as a communication tool. By tying specific knots in the rope, they could convey vital information. These knotted ropes were discreetly left in strategic locations, such as on roofs or the ground, for allies to decipher.
In extreme cases, a ninja might even resort to shaving their head and carving a message into their scalp. After allowing their hair to grow back, they would deliver the hidden message in person, only revealing the information by shaving their head again.
The shinobi's methods of communication were as resourceful as they were secretive, allowing them to relay crucial messages without detection and maintain their covert operations.
