Introduction to Cryptography with Coding Theory, 3rd Edition

2.5 Sherlock Holmes

Cryptography has appeared in many places in literature, for example, in the works of Edgar Allen Poe (The Gold Bug), William Thackeray (The History of Henry Esmond), Jules Verne (Voyage to the Center of the Earth), and Agatha Christie (The Four Suspects).

Here we give a summary of an enjoyable tale by Arthur Conan Doyle, in which Sherlock Holmes displays his usual cleverness, this time by breaking a cipher system. We cannot do the story justice here, so we urge the reader to read The Adventure of the Dancing Men in its entirety. The following is a cryptic, and cryptographic, summary of the plot.

Mr. Hilton Cubitt, who has recently married the former Elsie Patrick, mails Sherlock Holmes a letter. In it is a piece of paper with ...