Ottendorf Cipher
The Ottendorf Cipher is a historical book-based substitution cipher where each character of the plaintext is represented by a triplet indicating the page, line, and word in a pre-agreed source text. The sender and recipient must share the same book (or document) and numbering method. This method hides the message in plain sight by encoding it as seemingly mundane numbers, making it ideal for espionage and covert communication.
Book Cipher
The Book Cipher is a classical encryption method in which numbers in the ciphertext refer to positions within an agreed-upon text, known as the key book. Instead of substituting letters directly, the cipher uses an external document as the lookup table. Without the exact same book, edition, and formatting, the ciphertext is effectively meaningless.
Book Cipher: Encoding
By default, spaces and punctuation are excluded when counting positions. Letters are indexed sequentially as a continuous stream of characters.
Using the key text:
Beale Cipher
The Beale Cipher is a set of three ciphertexts that allegedly reveal the location of a hidden treasure buried in the United States in the early 19th century. Only one of the three ciphers, commonly referred to as Beale Cipher #2, has been solved, revealing the treasure’s contents using a book cipher method.