Tool for translating the Chappe alphabet (encryption/coding and decryption/decoding mode) used by the aerial/optical telegraph.
Chappe Alphabet - dCode
Tag(s) : Symbol Substitution
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Chappe Alphabet
Chappe Alphabet Decoder
Chappe Alphabet Encoder
Answers to Questions (FAQ)
What is Chappe alphabet? (Definition)
The aerial telegraph proposed by Claude Chappe uses by default a series of numbered positions: the Chappe code (associated with a vocabulary). However, several sources seem to indicate additional positions/signals/semaphores which would have been used to spell a word or a name absent from the vocabulary, these positions represent the Chappe alphabet.
How to encrypt using Chappe alphabet cipher?
The Chappe alphabet associates each letter with a position of the Chappe tower according to the table:
| A | .png) | B | .png) | C | .png) | D | .png) | E | .png) | F | .png) |
|---|---|---|---|---|---|---|---|---|---|---|---|
| G | .png) | H | .png) | I | .png) | K | .png) | L | .png) | M | .png) |
| N | .png) | O | .png) | P | .png) | Q | .png) | R | .png) | S | .png) |
| T | .png) | U | .png) | V | .png) | W | .png) | X | .png) | Y | .png) |
| Z | .png) | 0 | .png) | 1 | .png) | 2 | .png) | 3 | .png) | 4 | .png) |
| 5 | .png) | 6 | .png) | 7 | .png) | 8 | .png) | 9 | .png) | & | .png) |
| dCode.fr | |||||||||||
Note the absence of the J and the presence of the & symbol. Also, some sources indicate that the 0 directly encodes the value 10.
Example: CHAPPE is coded in signals
How to decrypt Chappe alphabet cipher?
Each position of the Chappe telegraph corresponds to a letter (or a number), deciphering therefore consists of translating letter by letter.
Example: is translated DCODE
How to recognize a Chappe alphabet ciphertext?
The Chappe's alphabet is made up of visual signals similar in all respects to the Chappe code (but the positions are different).
What are the variants of the Chappe alphabet?
It is likely that other alphabets and letter combinations were used.
Moreover, doubts remain as to the veracity of this alphabet. Its content (25 letters, 10 numbers and 1 symbol) is surprising, given the number of possible positions, the lack of correspondence for the J is surprising.
dCode uses the font made by Keiichiro @9SQ on Github here
When Chappe alphabet have been invented ?
The Chappe telegraph was presented in 1793, the Chappe code and therefore the Chappe alphabet probably date from this period.
Source code
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Cite as source (bibliography):
Chappe Alphabet on dCode.fr [online website], retrieved on 2024-11-16,
