Such measures include all provisions for secrecy, such as censorship, counter-espionage, cryptography, control of own communications, security of documents, camouflage, and applicable tactical operations.
"Sound Military Decision"
U.s. Naval War College
If Poe's purpose was to make a story of cryptography, think of some of the innumerable plots he might have used, and see what you think of the effectiveness of the one chosen.
"Selections From Poe"
J. Montgomery Gambrill
150. 30. Read Poe's article on "cryptography," included in his collected works.
"Selections From Poe"
J. Montgomery Gambrill