Ottendorf Cipher
Ottendorf Cipher is a classical book cipher technique that encodes a secret message by referencing the positions of words or letters within a pre-agreed text, typically a book, newspaper, or any shared document. Each element of the ciphertext specifies a page, line, and word (or sometimes letter), allowing the recipient to reconstruct the message by locating the indicated elements. The strength of the Ottendorf Cipher relies entirely on the secrecy of the chosen text and the agreed-upon indexing scheme.
Book Cipher
The Book cipher, sometimes called a running key cipher, is a classical substitution cipher that uses a pre-agreed text, often a book or printed document, as the key for encryption and decryption. Its exact origins are difficult to trace, but it became widely referenced in the 19th century and was popular among spies and clandestine correspondents. The principle is simple: each word, letter, or symbol in the plaintext is represented by a number, letter, or coordinate that points to a specific location in the chosen book.
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.