History Main / PublicSecretMessage

* In ''Literature/TheEndOfEternity'', a stranded time traveller publishes an advertisement in a newspaper containing a picture of a mushroom and the phrase:

* In Orson Scott Card's ''[[EndersGame Shadow of the Hegemon]]'' when Petra and Bean communicate by starting an e-mail signature meme: an image file of a dragon with a coded message in it and the words "Share this dragon / If you do / Lucky end for / Them and you", which reference the Dragon Army and Ender Wiggin.

* In [[ICarly iCarly]], in the episode ''iPsycho'', Carly and the gang need to get a help message out so someone will rescue them from Nora. She's watching their every move, so they ask if they can send a birthday video to their friend Gibby. With Nora watching, they make him a video which contains a secret message.

* Series/ThePretender: Argus asks for Jarod's help in this way by placing an ad in the newspaper.

* The staff at Steve Jackson Games were not allowed to release the title of one game supplement in the Power-Ups series, and the forum speculation was that they were trying to create a sudden burst of interest on release to fuel impulse buys. The author even said "I've been told that the secrecy around Power-Ups 5 does, indeed, have something to do with impulse buys." Earlier today an entire game's fanbase facepalmed at the release of ''Power-Ups 5: Impulse Buys''.

* CityOfHeroes has villains getting bank robbery missions in such a manner, by looking in the newspaper for encoded messages from their Brokers.

* [[http://xkcd.com/370/ This]] ''Webcomic/{{xkcd}}'' makes fun of the public messages in Redwall.

* Some US units used "code talkers" - radio operatives who would translate their messages from English into into a language that was unknown to Axis forces (typically a Native American language, for which at the time there were no textbooks and dictionaries in some cases).

* In ''MercuryRising'', a secret agency publishes messages in secret codes in the puzzles section of newspapers to determine how difficult they are for amateur code crackers. When a nine - year old autistic boy solves one thought to be particularly secure, conflict ensues between factions with opposing ideas about what to do about it.

* In the MaryRussell mysteries, Holmes and Russell frequently use the "agony column" of the ''London Times'' to send messages to each other in a kind of code.

* Series/ThePretender In ThePretender Argus asks for Jarod's help in this way by placing an ad in the newspaper.

Alice needs to send a message to Bob without Carol overhearing. Unfortunately for Alice, she can't simply meet with Bob in private to discuss it, and sending a private message is either physically impossible or would arouse too many suspicions. The solution? Send a message to everyone, but encode, encrypt, or word it in a way that only Bob will understand the message. Alice might disguise the message in such a way that Carol will think it's an relatively innocent item, such as an advertisement ([[TheOtherWiki Wikipedia]] lists this technique as "[[http://en.wikipedia.org/wiki/Steganography Steganography]]"), word it so that everyone but Bob will misinterpret the meaning, or simply make the message so hard to decode that only Bob could do it.

* ''DanceInTheVampireBund'' has an instance where Mina makes a public announcement, speaking in an ancient language as a challenge to another vampire, but with fake subtitles in Japanese.

* In ''TimeTrax'' Lambert would send messages to the future by placing coded personal ads in the newspaper.

* TheIlluminati in ''VideoGame/DeusEx'' use this interestingly. They communicate primarily by heavily encrypted e-mails, which they know their oppponents will pick up and read. However, the information isn't in the e-mail, it's in ''the encryption key''. Each key means "Meet me at place X, at Y o'clock, on day Z".

* In ''HarryPotterAndTheOrderOfThePhoenix'', Harry alerts Snape while making it possible to convince Umbridge he was shouting gibberish, by yelling "He's got Padfoot at the place where it's hidden!" to the entire room. Snape understands that "Padfoot" was Sirius' old nickname and "the place" was a location that Snape knows Harry's been seeing in his dreams.

* In ''RedDragon'', Hannibal Lecter places a personal ad filled with Bible verse numbers in a tabloid as a coded message (the numbers refer to the nth letter on the xth page of his edition of ''The Joy of Cooking'') to Francis Dolarhyde. The FBI decrypts it, and realizes that it told Dolarhyde where Will Graham lives; they send Dolarhyde another message to lure him into a trap, but he recognizes it for what it is.

** Although, as the example of the first two lines of a Verlaine poem broadcast shown in the movie ''TheLongestDay'' broadcast separately on June 5 and 6, 1944, demonstrates, someone in the Abwehr did correctly guess the import of such messages (in this case: "the landing in France is imminent").

* During WorldWarII, the Allies would send messages to friendly resistance fighters, spies and other clandestine groups behind Axis lines by making announcements over encryption civilian BBC broadcasts. While the broadcasts were open and able to be listened to by the Axis, the messages themselves would be meaningless phrases whose meaning would only be understood by the intended receiver.
** The Axis used analog computers such as the Enigma Machine to send radio messages they believed were too heavily encoded for the Allies to decipher. This provided incentive for the development of electronic computers by the Allies.
** Some allied units used "code talkers" - radio announcers who could encode secret messages into a common language such as English, then translate them into a language which was virtually unknown in the Axis forces (typically a Native American language) before the broadcast.

* In the second season of ''TheSecretSaturdays'', Argost starts sending Zak secret messages regarding crptids as part of [[ShowWithinAShow television show]] ''Weird World''.

* [[Series/TheWildWildWest James West]] communicates with his partner, Artemus Gordon, through the use of coded symbols written on a menu in one episode and via Morse code punched into a newspaper in another.

* In ''TrialByJournal'', Lily sends messages to the presumed dead Perry by calling him 'Hansel" (his character in a play) in the newspaper. In return, he calls her LAW, and sends replies via the painting everyone thinks a gorilla is making. It makes sense in context.

* In ''{{Rubicon}}'', a secret society publishes messages encrypted in crossword puzzles in newspapers.

* A variation is used in ''[[TheThrawnTrilogy Heir to the Empire]]''. Mara Jade needs to send a message to her boss, Talon Karrde, but there's no way to do so without the message being intercepted by an Imperial Star Destroyer in orbit. Luke Skywalker (who is with her at the time), suggests using a "counterpart encrypt" between his astromech droid (also with them) and his X-wing (in Karrde's possession). The unusual encrypt works; the X-wing's computer decodes the message easily, while everyone else is stumped by it (although the Empire, while unable to ''read'' the message, does at least manage to figure out that the message is ''using'' a counterpart encrypt). Karrde later sends a message back using the same method, via the X-wing.

* The protagonist of ''MotherNight'' by KurtVonnegut works as a radio propagandist for the Nazis in WorldWarTwo, but he is actually a spy for the Allies. He's given a list of things they want him to find out about the Nazis, and after he finds them out he communicates the answer on his radio show by, say, coughing in the middle of a certain sentence if the answer is "yes" and not coughing if the answer is "no", or by using a certain word he wouldn't otherwise use, etc.

* GeneRoddenberry had served in WorldWarII with a man named Kim Noonien Singh. They lost touch after the war. Roddenberry named two characters after Singh, hoping to attract his attention -- Khan Noonien Singh in the "Space Seed" episode of ''Series/StarTrekTheOriginalSeries'' (and ''Film/{{Star Trek II|The Wrath of Khan}}''); and Noonien Soongh, Data's creator in ''Series/StarTrekTheNextGeneration''.

* There's another example of a publicly-published crossword containing a hidden message for a particular person in ''OliversTravels''.