Semaphore Cipher

The Semaphore Cipher is a visual signaling cipher that encodes letters using flag positions. Each letter of the alphabet is mapped to a unique combination of symbols representing the positions of two flags. Historically, it was used for maritime and military communication, allowing messages to be sent across distances without electronic devices.

In this version, each letter is represented by a pair of symbols based on a standard semaphore mapping. Spaces between words are preserved, but the letters themselves are replaced by their semaphore symbol pairs.

Semaphore Cipher: Encoding

Suppose the plaintext message is "HELLO WORLD".

Plaintext:  HELLO WORLD

Encoding using semaphoreMap:
H → └┘
E → ┘└
L → ┌└
L → ┌└
O → └─

W → |┐
O → └─
R → ─┘
L → ┌└
D → ┘┐

Ciphertext: └┘ ┘└ ┌└ ┌└ └─ |┐ └─ ─┘ ┌└ ┘┐

Semaphore Cipher: Decoding

To decode, each symbol pair is mapped back to its corresponding letter using the same mapping. Spaces between words remain unchanged:

Ciphertext: └┘ ┘└ ┌└ ┌└ └─ |┐ └─ ─┘ ┌└ ┘┐

Decoding:
└┘ → H
┘└ → E
┌└ → L
┌└ → L
└─ → O

|┐ → W
└─ → O
─┘ → R
┌└ → L
┘┐ → D

Plaintext: HELLO WORLD

Semaphore Cipher: Notes

This version of the Semaphore Cipher demonstrates how a visual signaling system can be represented in text using symbol pairs. Each pair uniquely encodes a letter, preserving spaces for readability. Its security comes from obscurity: without knowing the exact mapping of symbols to letters, it is difficult to decipher the message. Historically, semaphore relied on timing and visual observation, but in text form, it functions as a symbolic substitution cipher.